Hydroponic Tanks: Everything you Need to Know

Hydroponic equipment

Consider your hydroponics tank the heart of your system. Your water reservoir, or tank, is what holds the very thing your plants need to live: the nutrient saturated water solution. Once you start looking into hydroponic tanks more, you’ll quickly realize that they’re more complicated than simply being a tub where you hold your nutrient solution. And that can get overwhelming. Don’t worry though, this guide has everything you need to know about hydroponics tanks:

The Function of Hydroponics Tanks

Hydroponics tanks are more or less the same in design and function, in essence. Naturally they hold the water and nutrients that will be delivered to your plants. How they do that is slightly different depending on the type of hydroponic system. Here’s a brief look at how hydroponics tanks function in different systems:

Ebb and Flow

Ebb and Flow systems are also called Flood and Drain systems. The tank doesn’t have to be located directly under or next to the growing tray, but it’s the easiest and most common setup. Using a water pump, tubing runs from the hydroponics tank to the plant tray, and floods the tray with water from the tank. The water reaches a certain level, and then gradually drains away. Many systems have a drainage line that returns unused water back to the tank.

NFT

Nutrient Film Technique systems work by moving water from the nutrient reservoir to plant tray in a constant stream. Roots sit in channels that the water then moves through (with the help of the growing tray at a slightly slanted angle). In this case, a pump is needed to move water up to the growing tray, although the tank can be located away from the plants as long as tubing permits.

DWC

In a Deep Water Culture (DWC) hydroponic system, the plants are suspended in a growing tray directly above the hydroponics tank. The roots hang into the water reservoir itself. Because of this, the tank has to be placed under the grow tray. Tanks in these kinds of systems need to have an air stone to provide extra aeration that they lack otherwise.

Drip

With a Drip system, it’s also more common to place the hydroponics tray directly underneath the growing tray. This also helps to conserve any runoff water. Drip systems get water to plants through tubing that brings water from the reservoir to the growing tray. From there, each plant gets water through holes placed in the tubing.

Wick

In a Wick type system, the hydroponics tank has to be placed directly under the growing tray. That’s because the tray has holes in it that allow an absorbent cord to connect from the tank into the tray’s growing medium. Basically the cord soaks up nutrient solution from the tank, the nutrient solution travels up the cord, and is then absorbed by the growing medium and roots.

Finding the Right Tank for Your System

The biggest part of putting the right tank in your hydroponics system is making sure it’s a good fit. While any old tub can surely hold water and function as your tank, if it isn’t sized correctly you end up with either not enough water for your plants, or a pointless excess. That being said, it’s far better to end up with a pointless excess. The capacity of your tank is going to mostly rely on your plants, but most hydroponic gardeners prefer to double the amount of water their plants need when sizing their tank.

Here’s how to make sure your tank is the right size:

First, take note of how many plants you have (or plan on having). Then also make a note of how many plants are small, medium, or large. If you’re unsure, it’s better to estimate up and account for the mature plant’s size.

Here’s a rule of thumb you can follow to determine how much water your plants need:

Large plants – require a minimum of 2.5 gallons per plant

Medium plants – need between 1 and 1.5 gallons per plant

Small plants – should get at least .5 gallons per plants

Look at your list of plants, and use the above list to determine how much water your tank needs to hold. Basically, just add up the gallons you need for each plant, and you’ve got your answer.

As an example:

Total plants: 12

Large plants: 2                                           Water needed: 5 gallons

Medium plants: 6                                       Water needed: 9 gallons

Small plants: 4                                           Water needed: 2 gallons

Total water needed: 16 gallons (minimum)

As you can see, it’s not difficult to see how much your tank needs to hold. In this case, the tank would need to hold at least 16 gallons, but a tank that could hold a few extra gallons would be better (and give you a good, safe margin). Keep in mind, that number is very much a bare minimum. Doubling the minimum water needed gives you 32 gallons, and a better chance of thriving plants.

So, You Want to Make Your Own Hydroponics Tank?

Making your own hydroponics tank is easy, and it saves on money. For that reason a lot of people choose to make their own DIY hydroponics tank. You can recycle tons of things into a new hydroponics tank, as long as it’s an appropriate size and water tight.

Here are some ideas:

  • Old fish tanks
  • Plastic storage bins (just make sure they’re deep enough)
  • Large display boxes (plastic or glass)
  • Plastic trash cans (thoroughly cleaned)

Tip: Before you decide to use anything as your hydroponics tank, you need to be 100% sure it’s water tight. Fill the ‘tank’ full of water, and inspect it thoroughly for any leaks. If you don’t see any, it’s a good sign but you still need to let it sit overnight to be sure. If you want to be really sure there isn’t any leak, put a thin material like toilet paper or tissue paper around the floor where your tank is sitting. Even if water from a leak evaporates, the paper will show there was a leak by sticking to the ground.

Once you’re totally sure your tank isn’t going to leak, you need to clean it. Even if you purchased a container to use as your tank, you still need to clean it. You can use disinfectants to be sure it’s sterile, but you can also use a 50/50 mix of water and vinegar.

Now that your tank is cleaned up, make sure to give it a water rinse and dry it (especially if you used chemicals or disinfectants).

Note: you’ll also need to get some other gear to go with your tank, such as a pump, air stone, inline tubing, etc.

Extra Components You May Need for Your Tank

Your hydroponics tank itself is one of the most important parts of your hydroponic system. Alas, one soldier can’t win a war, and likewise your tank is going to need some help to work properly. Some things are totally necessary to add, while others depend on preference or the type of system.

Nutrient Solution

Nutrient Solution has to be added to your tank so that your plants get sufficient nutrients. With proper testing and regular maintenance, it should be easy to get on a steady schedule for adding nutrients and managing EC levels.

Tubing

Tubing is a pretty simple component of your tank, but it is going to be responsible for connecting your pumps, airstones, water, and plants together. Always make sure the tubing you use is free of damage, and food safe.

A Pump

Pumps have an important part in hydroponic systems. They move water from your hydroponics tank into the plant tray, via tubing that connects from the pump, through the reservoir (or tank), and up to the plants. Pumps are either inline or submersible. That means that they’re either located outside of your tank (in inline models), or inside the water of your tank itself (in submersible models).

An Airstone

Airstones add extra oxygen to the water in your tank. Basically, they connect to a pump with tubing, and air is pushed through the tubing into the airstone itself. This produces tiny bubbles that aerate the water. Airstones aren’t required for every type of system, but they do improve the quality of the water in your tank whether required or not.

Hydroponics Tanks: Location is Everything

Well, to be fair location isn’t everything. But it can make a big difference to your tank. In some systems, like DWC, tank placement is non-negotiable. Your reservoir has to be placed directly under the plants. In others, like Ebb and Flow systems, your tank doesn’t necessarily have to be placed anywhere specific, so you’ve got some choice.

Here’s where a lot of people mess up:

In the attempt to create a convenient set up, they place their reservoir close to their plants. Usually, as close as possible. While it’s a good idea, it actually causes more issues than it solves.

The first problem becomes evident pretty quickly, and it’s algae. Placed so close to the heat and lights around the plants, algae flourishes. Not only that, your tank becomes a breeding ground for fungi, bacteria, and microbes that can wreak havoc on your plants.

And let’s not forget that your water’s going to evaporate more quickly, leading to higher EC concentrations and more frequent water changes.

Not only can you end up with all kinds of contaminants, your EC levels can become so concentrated that your plants end up with burned roots. With a high temperature, plants have less access to oxygen (as the available oxygen in the tank is seriously decreased) and can ‘drown.’

Another side effect is that high temperatures can create a snowball effect. Since plants have to perspire to release heat from the water, they have to drink more water as a result, and therefore lower water levels in the reservoir and increase the nutrient saturation even faster.

Some hydroponic growers go to great lengths to avoid these issues; even going as far as placing their tank in another (adjacent) room, or underground. You don’t have to go that far, but don’t put your tank too close to your plants if you don’t have to. 

Let’s Talk a Little More About Your Tank Temperature

Hydroponic tanks shouldn’t have unregulated, unmonitored temperatures. Really, after you’ve got your system all set up you shouldn’t have to do much with the temperature of your water. That is, as long as you’ve set it up properly and found a way to keep a stable temperature.

The ideal temperature range to aim for is around 63 to 72 degrees. This range suits most plants and prevents conditions that invite bacteria and disease like root rot. What might surprise you is that you’re going to spend more effort keeping your tank water cool enough, rather than warm enough.

If you can’t find a perfect, temperature stable spot in your growing area, don’t worry. It’s a very, very common issue so there are plenty of solutions. Here’s what you can do:

  • Move your tank into another area, or insulate it by placing it underground (too much effort? Most people are in the same boat, so read on).
  • Wrap or cover your reservoir in a shiny, reflective covering, or a light colored coating. This will deflect some heat from seeping into your reservoir.
  • You can also use insulated padding around your reservoir in conjunction with coverings that deflect heat.
  • The last solution is more expensive, so typically commercial growers or very invested hobbyists are more likely to choose this option: purchasing a water chiller.

Why Is Maintaining Your Hydroponics Tank Important?

Briefly, let’s talk about why tank maintenance is so important. Setting your tank up correctly is going to give you a good start, but it does little good if you neglect your tank. Tank maintenance includes everything from testing your water and adjusting water levels when needed, to changing out the water, to cleaning out your tank and equipment, to keeping a maintenance log.

Without due care, the water in your tank can become a harmful, toxic substance to your plants. When water undergoes drastic changes in quality, pH, or nutrient concentration, it can put your plants into shock, burn roots, or invite disease and bacteria. Properly maintaining your hydroponics tank prevents the dramatic changes in the water/nutrient chemistry, as you’ll be able to correct problems before they spiral out of control.

Regular cleaning and water changes should be on a schedule to allow helpful organisms to remain, while harmful organisms are regulated and controlled. Even allowing too much algae to accumulate can take away from your water’s oxygen levels and create an ideal environment for microbes and fungal disease.

Tank Maintenance Guide:

Once you’ve got your tank selected, you’re going to have to do more than dump water in and call it good. Proper tank maintenance can protect your plants from a ton of problems, and once you’ve got a maintenance routine down it really isn’t that hard. Here’s a rundown of everything you need to know to keep your tank in great shape.

Test your water

One of the first things you need to do is begin a testing routine for the water and nutrients in your tank. Test your water regularly, and once your system is established aim to test at least once daily, although twice is optimal (Tip: test at the same time daily for better results).  When you test your water, you need to be looking at two main things:

PH: pH, or potential hydrogen, should usually be in the range of 5.5 to 6.5

EC: EC, aka electric conductivity, measures nutrient levels in your water and should be 1.2 to 2.0.

There are different testing methods you can use, but the easiest by far is using a monitor. Some monitors are even available as an EC/pH testing combo. Other testing methods include strips that are dipped into the water and liquid testing kits (a sample of the reservoir water is taken and drops of the testing solution change color to indicate levels).

What if my pH or EC levels are off?

For pH, there are a ton of readily available, commercial solutions to either raise or lower your pH. If you use one of these, make sure you follow the directions exactly, and test your water during and after changing the pH levels. If your EC is too high, simply dilute the solution in your tank with clean water. Test frequently, and add water gradually until you reach the proper level. If your EC is too low, you need to add more nutrients to your tank.

Taking care of the water in your tank

Besides just testing, you need to make sure you’re giving the water in your tank proper maintenance (which will also help reduce EC and pH level issues). There are two main things you need to do to keep you water in top shape in between testing: water top offs, and water changes.

Topping off the water in your hydroponics tank

Your hydroponics tank is going to lose water gradually, so you need to compensate for that. It’s best to start a routine for this right away, and keep to it. Another thing you should be doing is keeping a log of water top offs, which you’ll need later on.

Water top offs are easy, simply add water when you notice that your water level is lower. When you do this, make a note in your log of how much water was added. That’s pretty much it, just be prepared to top off your water every day or two.

Doing a water change

Every once in awhile you need to do a larger water change to help keep your tank problem free. You’ll do this every couple weeks, or every few weeks if your water doesn’t evaporate very quickly. Basically, you need to keep an eye on your top off log to know exactly when to do this. Once the volume of water you’ve topped off with is half of your tank’s capacity (added up over time), it’s time.

Simply remove half the water in your hydroponics tank and replace with fresh water. As always, make a note of the change in your log and test your water for pH and EC levels.

Cleaning out your hydroponics tank

Your hydroponics tank can gather up a bunch of nasty gunk over time, and while there are helpful things in there (like beneficial bacteria), you have to clean it. It can be tempting to shirk this chore, but your plants will suffer for it in the long run.

First, how do you know when it’s time to clean your tank? Well, you need to go back to your logs. Again, if you’ve been keeping good records, this step isn’t so hard. Monitor your top off log and when the volume of water from top offs totals the volume of your tank, it’s time to clean. Here’s another way to look at it, if your top offs equal half your tank’s volume in 2 weeks, you’ll be cleaning your tank about every month.

Here’s a quick example (so you know when to clean your tank):

Let’s start by assuming that your tank is 10 gallons (remember, we’re keeping it simple here). Now, here’s an example of what your log for top offs and water changes would look like:

Note: As shown in the chart, the larger water change is done when top offs equal 50% of the volume (1/15/19), and a cleaning would be done on the date after the last logged top off (1/25/19).

What can you use to clean your tank?

There are commercially available solutions that you can purchase to clean your tank with. Generally, these solutions should be food safe, plant safe, and contain minimal chemical content. But you don’t really need to go buy a special cleaner. You can use vinegar, bleach, or hydrogen peroxide, and they do the job just fine. Here’s the thing:

If you use bleach, take care. Your plants can’t come into contact with it, so only use it when you’re not growing anything. Hydrogen peroxide and vinegar are both safe around plants in small amounts (although still make every attempt to maintain as much distance as possible).

Start cleaning with clean tools

Don’t go to clean your hydroponics tank with tools that aren’t clean. The reason behind this should be obvious, and it’s a small, easy thing to clean your tools before you start. Even things like scrubbers (if you’re using them) need to be cleaned thoroughly.

Drain your tank

Disconnect any ancillary equipment from your tank, from airstones to pumps to tubing. Then, drain your tank. It shouldn’t have to be said, but make sure you’re doing this well away from any electrical sources.

Clean it up

After that you can do a preliminary spray down (if your reservoir’s gotten pretty gunked up you may want to use a pressure washer). Then use your cleaning agent to sanitize your tank started at the top and working methodically downwards. To make sure you’re killing all the germs, bacteria, and microbes, you can let the solution sit for a few minutes. Then, rinse your tank thoroughly to get rid of any solution that may remain.

Let it dry

Look, letting things air dry can be pain and it does make a chore take longer. That being said, if you can let your tank air dry it’s actually better. You can manually dry it out, but you risk leaving behind fibers or microbes. Running a fan can help expedite the process if you’re not the patient type. 

Note: you will also need to clean out the other parts connecting to your tank, such as tubing and filters. You can use the same process and solutions as you did to clean your tank.

Hydroponics Tanks FAQ

My water levels are out of control! Should I do a full water change?

Resorting to a full water change off schedule is, ideally, something to avoid. That being said, you need to weigh the severity of the situation vs the benefits of a full water change. Keep in mind that the pH of the water alone should never change more than .5 at one time. More than that can shock your plants. So it’s better to do more frequent, small water changes (while testing at each change) until you reach a safe level.

Does my tank need to have a lid?

Technically, no it doesn’t have to have a lid. But let’s be honest, it’s a really, really good idea to have one. First, you’re going to lose a lot less water from evaporation. That means your EC and pH levels are going to be more stable. Next, you don’t want debris dropping into your reservoir and mucking up your water; a lid makes this a non issue. Also consider that with a lid, it’s going to make regulating your water temperature much easier, which is better for your plants and your water quality.

Which is better for testing, a strip kit, liquid kit, or a meter?

The strip and liquid kits are accurate, although they do have to be replaced. It can also be confusing if the colors that show results are unclear. A meter (especially a combo meter) is more of an initial investment, but you’ll never question your results, nor have to buy another after x number of uses.

Hydroponic Pest Control: How to Protect Your Plants

Aphids on Plants

When you’re using hydroponics to do your gardening, you don’t have the same risk of pest infestation that you do when outside. However, you probably still have some concerns about protecting your plants from pests. It’s a good thing to be vigilant, but it’s even better to prevent a pest problem before one happens. So here’s what you need to know about hydroponic pest control:

The most common pest problems in hydroponics

If you want to control pests, you first need to know what you could be dealing with. Here are some of the pests that you’re most likely to find if you’ve got pests in your system:

Aphids

A lot of people are familiar with aphids from school lessons, and here you thought you were done with them. But they do infest hydroponic systems, especially when your plants have too much nitrogen in their food source. They’re usually found around the plant stems and these little guys can be either black, green, or grayish/tan.

Whiteflies

Whiteflies can be tricky, but you can spot them pretty easily. They look like tiny white moths (about 1mm long), and fly away as soon as you’re about to catch one.

Spider Mites

Spider mites are even smaller than whiteflies, at under 1mm in length. And they’re definitely one of the most dreaded infestations of a hydroponic system. They do look like tiny spiders, but since they’re so small they can easily escape notice until an infestation gets way out of control.

Fungus Gnats

Fungus gnats are another tricky pest, since the grown gnat isn’t harmful but the larvae is. You’ll find the pest larvae eating at roots, which can bring on bacterial infections pretty quickly. 

Thrips

Thrips, like aphids, can turn leaves yellow or brown because they suck the nutritients out. They’re a little bigger at 5mm, but still hard to spot. They’ll look like small, black dots on the upper sides of leaves.

Avoid things that ‘invite’ pests into your growing area

There are certain ‘good practices’ that can help reduce the chances of a pest making its home in your hydroponic system. Fortunately, a lot of these practices involve a little know-how, and a bigger dose of avoidance. That means one of the best things you can do is avoid introducing opportunities that appeal to pests.

Don’t go in dirty

Before you enter your growing area, you should be wearing sterile (or at least clean) clothes. All kinds of bacteria, pests, and other contaminants can cling to our clothing totally unnoticed. Even if you don’t think there’s anything there, just don’t risk it. A pest problem is a high price to pay for skipping 2 minutes to get ready to enter your growing area.  You’re not done yet though, your tools and anything you bring into your growing area needs the same care.

Basically: don’t bring anything into your growing area that isn’t clean and contaminant free.

Give your system a sterile start

If you’re setting up your system, or doing a little work on it, see the tip above. Even fixtures, vents, tanks, and any other gear needs to be cleaned before they’re introduced into your growing area. Period.

Checking the quality of the seals around your growing area is important, too. While you want a well ventilated area, you don’t want a free for all for pests. Make sure there isn’t an issue with seals on windows and doors to outside areas (especially when your growing area is close to outside vegetation). 

Outside Materials

Pests can crop up from some sneaky places, and the materials you introduce into your hydroponic garden are an unassuming hiding place. The pest home that we inadvertently bring into our hydroponic systems?

Growing medium.

Look, this isn’t to create a scare campaign because the truth is most growing mediums are perfectly sterile, and safe. But there are some things to look out for. If you’re getting an organic growing medium, such as coconut or rice husk, pay special attention. These mediums can harbor pests, so they need special treatment. Make sure that your growing medium has been sterilized, put through treatments to eliminate pests, and has some credible backing behind those claims.

New Transplants (take care)

Whenever you’re planning on adding transplants into your system, you need to be careful. Outside plants can carry bacteria, fungi, diseases, and pests. To combat these risks, you need to get any transplants from a clean, well maintained place you can trust. And before you go transplanting anything just because it came from a ‘reputable’ facility, take the time to examine the plants for any health issues.

The first steps in hydroponic pest control

Pest control can be something you start practicing with at the very start with your hydroponic system. Basically, putting in measures that deter pests is going to be your first line of defense. Here are the best ways to prevent a pest problem:

Watch your humidity

Some pests, like spider mites and fungus gnats, are especially attracted to low humidity and excess moisture in other parts of your system. Keeping your humidity from getting too low (50% is a good level to keep plants healthy and keep mites away), can prevent an infestation. But it isn’t all about your ambient environment. Keeping too much moisture from your growing medium can deter pests, like fungus gnats, from taking up residence (especially if you use rockwool, which they love).

How to identify a pest problem

Even with diligent prevention, you can still have a pest sneak its way into your system. Like any hydroponic set up, you should be examining your plants for problems regularly. That being said, you don’t want to confuse signs of pests with signs of other issues, such as nutrient deficiency or disease. Here’s how to tell if your plants are suffering from pests, or another ailment:

Discoloration:

When pests suck the nutrients out of leaves (like aphids do), you’ll notice that the leaves become discolored and often turn a yellow color. This discoloration is centered around tiny holes that the pests feed from, not just generally spread on leaves.

Spots

Some pests can leave a signature pattern of spots, whether white, yellow, brown, or black.  If you notice spots, check to see if they’re deposits on the leaves (from eggs, feces, etc), or actual damage to the leaves. If the spots scrape off, you can pretty well bet you’ve got a pest issue.

When you notice these on any plant, check the leaves and stems of other plants to determine the pest and the degree of infestation.

Holes from pests vs burns and lesions:

When you first see a hole or rip, it can be easy to make assumptions. That’s why it’s important to look closer and check out the edges of any holes. Burns should be fairly obvious, as they’ll appear where light and heat sources are close to plants, and show discoloration around any holes or burns.

The pests that are most likely to infest hydroponic gardens are more ‘suckers’ than ‘munchers.’ That means the holes they leave from feeding on plants are tiny, and often raised and surrounded by a more yellow, or whitish area.

What to do when you have a pest?

If you’ve noticed some of the above symptoms of a pest problem, you need get it fixed and quickly. Unfortunately when a pest has already made its way in, it can be difficult to mitigate the issue.  Pests can run through a hydroponic system at a surprising speed, so once one plant is affected the others tend to follow in short order.

Don’t wait to take care of a pest.

If you act immediately after spotting pests, you may be able to spare the rest (or remaining unaffected) of your plants. If you wait, you’re probably going to come home to a garden that’s been almost, if not entirely, infested.

Determine the level of intervention needed:

Some pests can be taken care of by changes to the environment, manual removal, or other methods, while some pests can only be banished with chemicals. Whenever possible, avoid introducing harmful chemicals into your hydroponic system.

More gentle methods of pest removal:

Sticky traps

One of the first things you can do, depending on the pest you’re dealing with is use sticky traps. These work like the other sticky bug traps you’re familiar with, and can be really helpful especially with pests that have short life cycles. Another bonus of using sticky traps is that it can help you identify the pests infesting your system. If you can identify the pests, you can take a more appropriate route to getting rid of them (even if sticky traps don’t eliminate them).

Tip: Keeping sticky traps can be a preventative measure, too. If you see pests caught on a trap you can prevent a larger issue.

Natural solutions

A lot of solutions are marketed for killing pests, but you don’t want to chance killing your plants too. When in doubt, make sure your solution is backed with plant safe guarantees. A solution you can rely on, without a doubt, is Pyrethrin. It sounds very chemically intense, but don’t worry. It’s been given the green light for even certified organic farmers to use, so you know it’s safe. Pyrethrin is extracted from chrysanthemums, and can put a stop to pests.

A good spray down

Oftentimes you can give your plants a good hosing down to start getting pests under control. True, it won’t kill all your pests, but it can disrupt another cycle of reproducing, and it’ll get the bulk of them off your plants.

Hydroponic pest control: The cheat sheet

If you’ve found yourself with a pest problem that quickly becomes an emergency, here’s the cheat sheet you need.

Symptoms:

  • Black spots on leaves – see Thrips
  • White or yellow spots – see Spider Mites, Whiteflies, Thrips, Aphids
  • Deformed stems or leaves – see Fungus Gnats, Aphids
  • Deposits on leaves – for silvery streaks see Thrips, small black see Thrips, sticky residue see Aphids, white masses and clumps see Mealybugs
  • Webbing around plants – see Spider Mites

Pest information and treatment

Aphids

Aphids secrete honeydew, a sticky residue that stimulates the growth of sooty mold (honeydew can also attract other pests such as ants). These creatures such nutrients out of leaves and can leave them looking yellow and crinkled.

Tell-tale signs:

Aphids leave behind a good deposit of honeydew when they’re feeding, so you’re unlikely to miss these deposits. You can usually spot the aphids moving around stems, although they can be a variety of colors.

Treatment:

You can use predator bugs that feed on aphids to control their infestation; ladybugs and lacewings are the most common choices. Safe soap pesticides contain different formulations, but most are safe for plants and deadly for pests. Leaves, stems, or even whole plants that are severely infested may need to be removed. Next, try not to overfeed your plants, as that will increase aphid problems. 

Fungus Gnats

Adult fungus gnats are annoying but not a huge problem (aside from the fact that they reproduce). The larvae are going to be your real issue, as they congregate near and fed on the roots.

Tell-tale signs:

The first sign you may notice is the adult fungus gnats that fly up in masses whenever you disturb a nearby area. The larvae can be found by looking at the growing medium, and turning it over a bit. The plants they feed on start by looking ‘ill,’ meaning they get yellow leaves, look wilted, and seem frail.

Treatment:

First, avoid these guys by trying not to overwater your plants; but if you’ve already gotten to that point, try letting the growing medium dry out as much as possible, to a couple inches from the surface before adding any more moisture. You can catch eggs with sticky traps near the medium, and introduce nematodes to take care of the larvae. Neem oil can also be sprayed for severe infestations.

Mealybugs

Mealybugs love fruiting plants, so if you’re growing the like you’re more likely to see them. These are another ‘sucker’ type of pest, so you’ll notice weak, yellow leaves if an infestation becomes larger.

Tell-tale signs:

Mealybugs leave eggs in white, cottony looking masses on the undersides of leaves and stems (although they make be located anywhere on the plants). They leave behind a honeydew residue, much like aphids, and generally have a waxy coating.

Treatment:

Solutions: you can treat Mealybug problems with a gentle, natural pesticide or insecticide. You can also use a solution of 1 oz Neem oil with 1 gallon of water and spray every 1 or 2 weeks until the infestation is gone. Some helpful insects such as ladybugs can also be used.

Tip: if you catch an infestation early, you can manually destroy egg sacks with a swab soaked in alcohol and then remove them.

Spider Mites

Spider mites leave fine webs all over plants, and can be a difficult pest. They tend to infest areas with high temperatures and low humidity.

Tell-tale signs:

First, the webs. Spider mites leave behind sticky webs, just like regular spiders, but smaller and finer. Since they also suck nutrients from leaves, you may notice yellow and whitish spots on leaves. They can grow in number quickly before you notice webs, so check the undersides of leaves where they gather.  

Treatment:

First, manually remove areas of high infestation by pruning and removing heavily infested leaves and stems. Then you can use a safe, organic insecticide or biological insecticide to get it under control. A mixture of Neem oil and a wetting agent (for better spread) can also be sprayed every few days to kill mites and eggs.

Thrips

Thrips can grow huge populations in a short amount of time, and a heavy infestation can cripple a garden if left untreated. These hyper active pests are especially attracted to light colored plants and flowers.

Tell-tale signs:

One of the biggest signs that you’ve got a thrip problem is black spots on the leaves. The black spots are actually feces dropped onto leaves. You’ll also notice that the plants they feed on get discolored spots and may appear dry.

Treatment:

The first thing you can do to get rid of thrips is release some insects that feed on them. Lacewings and ladybugs are typical beneficial bugs, but minute pirate bugs are most effective when it comes to thrips. If the problem grows too large, pyrethrin can be used, and followed with an insecticidal soap when needed. 

Whiteflies

Whiteflies hide on the undersides of leaves and look like miniature moths. Like fungus gnats, they fly up in large crowds when disturbed.

Tell-tale signs:

Like aphids, whiteflies leave a sticky honeydew residue that you can spot on leaves (as well as any sooty mold that’s grown as a result). You may also see light, discolored spots where whiteflies have been feeding on leaves. Once an adult population has been established, you should be able to easily tell if they’re in your system.

Treatment:

To begin reducing the infestation, spray plants with water at a moderate pressure, and begin introducing beneficial insects. Like most pests, you can use ladybugs and lacewings to reduce them, as well as the whitefly parasite. Organic soap insecticides can get rid of them quickly, as can spraying with Neem oil.

What Grow Lights are Best for Hydroponics? A Complete Guide

Hydroponic Grow Light

While many growers struggle with some of the many variables when running a hydroponic system, they can overcome these, and come to understand how things work. However, for newer growers, there is one area that can cause persistent problems, and seems to elude them how they can conquer it and fully understand it.

This is lighting, and it is one of the most crucial aspects of any hydroponic system. The thing is, there are so many lighting types available, and each set of plants can react slightly different to lighting if conditions aren’t exactly the same.

The hardest part for new growers is deciding which lighting system is the best. This can be difficult to understand because each lighting system offers very different characteristics than another. It isn’t a matter of giving plants any old light, it needs to be the correct sort of light, and knowing which lights can deliver this is half of what causes the problems.

There are plenty of lighting choices, so here we will run through each type to see how they operate, and what is unique about them.

It should be noted that when purchasing lights, apart from LED lighting systems, they are given a rating which is measured in lumens. These lumens bear little in relations to plants and are a scale that we, as humans use as a means of determining brightness. For plants, the main thing is the Kelvin rating which is a scale and relates to the different areas of the color spectrum.

A light might be bright to us, but to plants, the light may not be doing anything.

How Lighting is Measured

Before going through the various lighting types, it is good to see how light is measured, and what each bulb has to offer.

There are a few ways that light is measured, but some are almost obsolete, but still used in some things. Foot-candles or candle power is one such term, and this often relates to flashlights or spotlights that shine in millions or thousands of candle power.

Temperature is one of the primary terms you will see when growing in hydroponics and when looking for the ideal light. This temperature has nothing to do with heat output, but it is a reference to the natural color of the light produced.

When we see cool lights, these deliver light at the blue end of the spectrum while when we look at lights which are warm looking, these are providing light at the orange/ red end of the spectrum.

Lights can be measured by watt power, nanometers (nm), or Lumens most often. The watt power is the units of energy required to run the lighting, and it is the term most people are familiar with. When it comes to grow lights, these are often rated to the number of watts needed for each centimeter squared of the surface to be illuminated.

Lumens is a reflection of how bright a grow light is, and although used, these lumens are not actually a rating that does anything for the plants. The light required by plants is beyond the physically visible spectrum.

When light is measured in nanometers, this is actually the light we can see. This visible light falls in the range of 400 to 700 nm. When you compare this to the color spectrum, the warm or red end will be reading 730 nm, and at the other end in the color part of the spectrum (violet), this will be reading 400 nm.

Almost all grow lights fall in the range of 450 nm to 730 nm. These are the most crucial nm measures with one addition of 650 nm in the middle of the spectrum.

We all know that plants need to photosynthesize, and for plants to do this, there is the need for a light at the 450 nm and 650 nm levels. With these, plants can create the food it requires from the light available along with water and carbon dioxide. It is the green pigment where chlorophyll is produced.

When plants use the 650 nm and 730 nm ranges, this allows them to control their flowering through another pigment which is called phytochrome.

This is why the full spectrum of light is required at varying stages of a plants growth, and this is why it is crucial to have the best lights that allow growers to replicate this.

Here we will take a look at each lighting system, and see what they offer for plants, and hopefully, we can determine which are the best lights for hydroponics.

Fluorescent Grow Lights For Hydroponics

These lights have been around for years, and they are an economical bulb to run. One other main advantage is they run cool and can be placed very close to the top of plants with no fear of burning. However, this plus point is also highlighting one downside of these bulbs. The light they give out isn’t strong enough to penetrate past plants outer foliage or leaves.

One of the latest improvements is the introduction of the T5 bulb system, but there are a couple of things to know for this lighting type.

T5 Lighting Fixtures

With these, you can find more than a dozen variations in size. Knowing the dimensions for your growing area can be crucial so you will need to calculate growing space and then calculate your lighting needs.

There are usually two lengths that these bulbs can be found in, which are 2ft or 4ft in length. Along with this, some fixtures sizes can hold either 1, 2, 4, 6, 8 or 12 lighting tubes. This delivers lots of flexibility once you calculate your grow space. The rule of thumb is a small space with a few plants you can use a 2 or a 4ft light that has 1 or two bulbs. Larger areas and more plants, you will need a 4ft fixture with more bulbs.

T5 Bulbs

One of the largest draws toward T5 tubes is that they cover different color temperatures. Although it is hard to give an exact figure which meets different growers requirements. Choosing a bulb that delivers 6,500 Kelvin is a good starting point for plants in the growth phases. For flowering, bulbs that offer 3,000 Kelvin are more suitable.

There is also 3 outputs for T5 tubes, these are NO (Normal Output), HO (High Output), and VHO (Very High Output). To get the best of both, the HO (High Output) is a good recommendation. These are energy efficient while delivering plenty of good light, and are long-lasting.

T5 grow lights can be placed 6 -8 inches above your plants. If you have seedlings, or your plants are showing signs of dislike, raise this to 12 inches.

Pros

  • Cheaper than most other lights
  • The emitted light can cover larger areas than other lights
  • Versatile and long lasting

Cons

  • Not the best choice during vegetative growth stages
  • Not the most suitable for flowering stages

 

HID Lights for Hydroponic Systems

HID’s (High-Intensity Discharge Lights) are systems which come with much larger bulbs than other systems. These work by a gas being ignited inside the bulb. This is done by electrodes that sit close together, and when a current is passed through these, the gas becomes ignited.

This type of bulb is available in two varieties, but the third being a hybrid of the two.

  • MH – Metal Halide: These burn gas that produces lighting toward the bluer end of the lighting spectrum. This is beneficial for the vegetative stage of a plants growth cycle.
  • HPS – High-Pressure Sodium: This bulb type produces light that sits toward the red/ orange end of the spectrum and is much better for plants that have reached their flowering stage.

The problem with all HID bulbs is they need other components to run and be effective. These are as follows:

  • Ballast – this is what helps the bulb start when it is turned on, and it also helps to maintain the flow of electricity. These come in two forms and are a magnetic ballast that uses coils and a condenser to regulate power, and the second is the newer digital ballast options. These are more effective and cost-efficient when running.
  • Reflectors – these are, in the purest form a light steel hood which sits above the bulb to force light down to the plants.

HID’s lose their (Lumen) effectiveness by almost 70% once they have been used for a total of 10,000 hours or more. To put this in perspective, if you ran the lights for 14 hours per day, this is around 2-years. However, there are a lot of growers who monitor their lights closely and change them well before this period is up.

But, even with this need for changing on a regular basis, these are very effective bulbs. They deliver very active UV rays through the light that is given to plants, and with this comes some very productive photosynthesis.

Pros

  • Can be dimmed, so customizable light can be delivered
  • Digital ballast allows for all HID bulbs to be used
  • Deliver better usable light than T5’s

Cons

  • Can burn plants if placed too close
  • Require additional components to operate – ballast, reflectors
  • Bulbs loose effectiveness over time – require frequent changing

Led Lighting Fixtures

These lighting fixtures have been around for a little while, but they are still new in hydroponics for a good number of growers. Although they are still relatively expensive, they do come with numerous benefits over other lighting systems.

Luckily, as they gain more popularity, their prices will continue to fall. However, some manufacturers produce lights that deliver lower amounts of light. When looking to purchase, be sure the lights you look for are 2.0 micromoles per watt of energy as a minimum.

These cheaper LED systems aren’t enough to support flowering plants, so it is essential to do some homework beforehand. This can change depending on the type of plants being grown, but hopefully, these subpar systems will vanish when costs fall.

One final thing to note when looking to buying LED lighting systems is that many are sold as being all in one unit. In some cases, this isn’t the case, and there is a need for reflectors to be used with the LED lights.

Pros

  • Very energy efficient, and are among the cheapest light sources to run.
  • LED’s produce more light per watt of energy than both HID’s and fluorescents. But with some exceptions
  • The LED’s run much cooler, so there is considerably fewer chance plants will be burned
  • LED’s are very long lasting, and in many cases, it is the control unit which fails before the bulbs themselves
  • LED’s don’t need any ballast to operate and can be plugged directly into the mains socket
  • LED’s cover a wide range of the color spectrum and is adjustable so they can be tailored to your plant’s needs and stages of growth
  • LED’s are now known to be the easiest to use

Cons

  • At present, these lighting fixtures are more expensive than the alternatives
  • Some of the lighting systems throw out less light than other varieties of grow lights.
  • Some manufacturers produce lights which don’t have the power to support plants when they are in their flowering stages.

Alternative Grow Lights

Although these are the primary three lighting systems, and with good reason. They all have their benefits, but this still isn’t good enough for manufacturers. They keep on striving away to produce more efficient and cost-effective solutions.

Here are some of the alternative lighting systems you might be hearing of and seeing more of in the near future.

Induction Lighting

These are basically new versions of CFL’s (compact fluorescents). The way they operate though, is pretty technical. What they do is to ignite a gas compound that is generated by means of magnets. For this, there is no igniter, and everything happens inside a sealed tube.

Their light creation process produces less heat than it does light. This gives them a theoretical range of 100,000 hours which is way above any other system.

One problem they do have is, they can interfere with cell phones and Wi-Fi signals

Pros

  • Almost double the efficiency of other fluorescent lights
  • The theoretical lifespan of the usefulness of over 15 years
  • Cool running so they can be placed closer to the tops of crops
  • Instant on compared to lights that require a warm-up period

Cons

  • Noisy in operation
  • Too new, so still very expensive
  • Still not as efficient as HPS or LED’s

Double Ended Lighting

DE (Double-ended lighting) is relatively new and is a form of HID lighting system. It follows the HPS bulbs, but rather than being a single ballast socket. It is a double ended tube which connects to the ballast at both ends. While there are a few similarities to HPS, they do have key benefits and also downsides.

Pros

  • DE lighting has a longer lifespan than their single socket counterparts.
  • More efficient – these bulbs can retain as much as 90% of their efficiency compared to previous bulbs over the same amount of hours usage.
  • Thin tubes allow for closer plant placement compared to single ended bulbs

Cons

  • Although they can be placed closer to plants, they do run hotter and can cause leaves to burn
  • Direct airflow reduces the efficiency of the lamp while in operation

Sulphur Plasma

These bulbs burn gas at very high temperatures, and in effect, they are replicating the sun. At present, all the information is still in developers hands because these bulbs are still new and in testing.

At present, there are only pros and cons to be shared, but no doubt, if these are found to be beneficial, then every grower will quickly hear about them.

Pros

  • The bulb has the potential to create almost natural light because the spectrum of generated light is close to that of the sun.
  • If successful, these can be the best option for larger grow rooms, or where bulbs can’t be placed close to crops.
  • The lifespan is expected to be 3X or 4X the length of other forms of traditional hydroponic lighting systems.

Cons

  • Not suitable for smaller grow rooms because they burn so hot
  • Fixtures are large and bulky
  • Very expensive

Conclusion

As you can see, not all grow lights are created the same. Each comes with its own benefits, and also its own unique downsides.

On top of this, is the fact that all grow rooms are very different, so there are countless other variables growers need to consider. Lighting is only one part of this puzzle, but it is evident, no one lighting system is perfect.

Growers need to understand all of their plant’s requirements, and also what they want from their plants. When they know this, they can put things in place, and choose the best lighting system that their budget allows. Even then the choice may not be so simple, but at least growers will know the options they have, and which lighting systems are most suitable for them.

Hydroponics for Kids: A Complete Guide for Parents

Hydroponics for Kids

Today our kids are flooded with technology and it can be hard to get them interested in some good old fashioned gardening. Thankfully there’s a way to garden that can be as technical as it is timeless: hydroponics. Hydroponics, at its heart is simply using water to deliver nutrients to plants rather than soil. It doesn’t have to be the commercial scale plant factories that you see on news reports, nor does it need to be a complex system with artificial lighting and running pumps (although you can do that too). The other really cool thing is that there isn’t any age, space, or resource limit on what you can do with hydroponics for kids.

Here we’ll go over everything you need to know about hydroponics for kids of any age. The activities listed do come with recommendations for age, assistance, materials, and complexity, but feel free to tweak them however you like. One of the most fun parts of hydroponics for kids is that it allows them to observe and innovate.

Why is hydroponics for kids a great thing?

We could fill a library with reasons that hydroponics for kids is a great thing. But in the interest of getting to the fun stuff, we’ll just talk about the best reasons.

They’re getting a piece of the past, and future

Let’s be honest, hydroponics is the future of crop growth. That alone is a good enough reason to get a kid interested, but it has a deeply historical past in human civilizations too. When you do a hydroponic project with your child, you get the opportunity to introduce important historical innovations with them. Being able to show them hydroponics is a way to help kids engage in history.

If their interest really sparks, they can continue their education about hydroponics and translate it into a valuable future career. The field of hydroponics is rapidly expanding, a lot like computers at their onset. While the first computer engineers may have been considered unusual or eccentric, they’re some of the top earners in today’s world. Hydroponics is becoming a similar phenomenon (with the exception of the eccentric engineer archetype, of course!).

You’re giving them a valuable life skill

Hydroponic systems provide an incredibly valuable asset to people all around the world. Hydroponic systems don’t need to be expensive or complicated to successfully produce food. Knowing where your food comes from is more important than most people give credit for, too. By helping your kid to understand hydroponics, they can see how plants grow up close, and they’ll be able to see how plants develop to produce their fruits or flowers.

Beyond creating a deeper understanding of botanical growth, they’ll be learning simple systems that they can use to grow their own food. Our society isn’t one in which where much of the population grows their own food. That being said, for humans as a species being able to produce our own sustenance is hands down one the greatest assets and skills any individual can cultivate.

Kids can get a close up look at science

Watching plants grow is actually pretty fascinating for kids, but they can lose patience when they have to wait to see progress. When they’re growing plants in soil, the wait is especially hard for two main reasons: until plants sprout, there’s a lot of wait while they look at a patch of soil. Next, soil grown plants grow much slower than plants grown hydroponically.

When kids get to grow hydroponic plants they still get to see the plants in progress while they wait for the plants to grow bigger. They get to see the seeds sprouting from the very start, and they can watch the root systems expand without the visual shield that soil creates. This also helps them understand the importance of root systems, which often gets passed over with the excitement of the rest of the plant.

Monitoring the plants, checking nutrient and pH levels, these are all parts of the scientific process of observation. When they’re observing something they had a large part in creating, kids are way more engaged than if they were just taking notes on what a specimen someone else grew looks like.

Here are the basics of what you need to know before you get started:

First, like we talked about, hydroponics is growing plants in water culture, rather than soil. So it’s important to explain how plants receive nutrients, how we can provide those through without soil, and what the water needs to do to get nutrients to the plants.

So here’s your cheat sheet:

Plants absorb nutrients through their roots. When they’re in the ground, the plant roots absorb nutrients and minerals by sucking up moisture from the soil. The soil, in turn provides the nutrients that the plant gets from that moisture. That’s why dry soil doesn’t grow plants (with a few exceptions of course, like cacti that use very minimal moisture), and that’s also why even very well watered soil won’t grow plants if there is no usable nutrient content.

In a hydroponic system, you don’t use soil (that would otherwise be responsible for providing nutrients), so you have to add plant food to the water. The plant roots absorb the water just as they do in soil, but they get more out of it.  To add the plant food, you’ll have to add a special ‘nutrient solution’ that’s meant for growing plants in water. Depending on the kind of system you use, the water travels to the water in slightly different ways. Generally though, the water is delivered to the roots through the system at certain times, almost like a very frequent, very small rain cycle.

Next, there are passive and active water delivery methods

Water is delivered to plants in either passive or active means. Active systems use some kind of powered equipment (even a simple pump) to deliver water and nutrients. Passive systems rely on absorption, gravity, or placement to get water to the plants.

Passive systems are easier for younger kids to work with, but both are pretty simple and equally fascinating.

What kinds of things do you need to start a hydroponic system with your kid?

Another reason introducing kids to hydroponics is so great is because it’s incredibly cheap (and if you’ve got the supplies around the house, it’s free), and supplies are easy to obtain. Really, a lot of the components you’ll need can literally be found right in your recycle bin, right now.

We’ll take about specific systems you can build with kids, and the specific things those will need, but there are some things you’ll need regardless of your system type.

You need something to serve as a water reservoir. This can be a plastic tub, old fish tank, or even recycled plastic bottles. You’ll also need to make a growing tray which will hold your plants steady and elevate them about your water reservoir. Plastic cartons, styrofoam egg trays, microwave meal trays, and just about anything flat and appropriately sized will work. 

Next, you’ll need seeds or saplings. Seeds still sprout faster when you’re growing them hydroponically, but kids are impatient. So here’s a tip that will change how you germinate seeds:

Put a few seeds in a damp paper towel and fold a few times. You want to end up with a rectangle about ¼ to ⅓ of the size of the paper towel before folding. Then put your folded paper towel into a sandwich bag and set it aside. After as little as a day you can see roots emerging from the seeds. After a couple days, you’ll see chutes and even leaves (but you want to remove them ASAP if you see this starting).

Just be careful not to leave the seeds in too long, or their roots will tangle and weave into the paper towel.

Here’s a rundown on the best kinds of hydroponic systems to introduce kids to:

Yes, hydroponic systems all work on the basis of water doing the work. With that understood, there are still different system types. Here’s a rundown on the best types of systems to introduce kids to:

Wick

Wick systems are passive systems, so you don’t have to worry about powering it (with kids, easy is awesome). Basically, a wick system has plants held in a growing tray (held in place with a growing medium) situated above your water reservoir. A super absorbent ‘wick’ (or cord or rope) reaches from into the water and up into the growing medium in the tray.  The plants then absorb the nutrients from the moisture in the growing medium.

DWC (Deep Water Culture)

Deep Water Culture systems are another great system to introduce kids to. While they do require more equipment and a bit more maintenance, they’re still much lower maintenance than other systems. DWC systems have plants suspended above a water reservoir, usually in a board (or you can use styrofoam, plastic etc), while the roots hang below and into the water. The most common set up uses net pots to hold each plant’s roots together. Nutrient solution is added to the water, and the roots absorb it directly.

With this system, you will need to provide some kind of aeration to the water.

Cool learning point:

Without sufficient aeration (i.e. oxygen in the water) plants can actually ‘drown’ in water.

To prevent your plants from suffocating or drowning you need to add an air pump or air stone to your reservoir. In much smaller systems like the ones kids will make, you won’t need a large expensive pump.

Other system types

Wick and DWC systems are the easiest for kids to operate and understand. In the interest of providing a complete guide however, let’s take a look at the other common hydroponic systems:

NFT (Nutrient Film Technique)

Nutrient Film Technique systems don’t submerge roots entirely, instead they continuously provide a light flow (or ‘film’) of nutrient solution (water with nutrients added) over roots. Plants are placed above a grow tray where roots lay in shallow channels. The tray is placed at a slight angle, and nutrient solution is pumped through the channels to flow over the roots. Once the solution has reached the other end of the tray, it flows back into the water reservoir.

Drip

Drip systems pump water from a reservoir to tubes that are placed near each plant. The tubes have holes placed near the roots of the plants that provide drips of water at periodic intervals. The plants sit in a growing tray with a medium to stabilize them. A pump moves water from the reservoir, up through the tubes, and into the grow tray. Usually a timer is connected to the pump to establish a watering cycle.

Ebb and Flow

Ebb and Flow systems also use a water pump and timer. Basically the plants sit in a grow tray above the water reservoir, and like with drip systems a timer regulates when the pump begins the water cycle. When the water is pumped to the plants, the grow tray is flooded (to a certain point) and then gradually drains back into the reservoir.

Projects to teach kids about hydroponics

The beauty of teaching kids about hydroponics is that it’s so easy to to demonstrate. Most kids learn better when they get a hands on experience, so hydroponics is a great way to teach them about plants.

Here are some hydroponic projects you can do with your child:

Wick system for kids

Suitable for ages: Preschool and up

Assistance needed: minimal

Difficulty: very easy

Materials needed: minimal

Cost: minimal to nil

This project is super easy, and best of all, it requires basically no maintenance. You’re just setting up a very simple wick type system. It’s better to do this project to grow 1 to 3 plants, at the most. Here’s how to set it up:

Gather your materials:

  • A tray to use for your growing tray
  • Watertight container for your water reservoir
  • Growing medium
  • Seeds or saplings
  • Nutrients (plant food)
  • Wick, aka cotton based absorbent fiber (clothesline works well for this)

Prep:

Start your seeds using the tip above (with damp paper towels).

If you’re using a plastic tray or bin for your growing tray, you’ll need to drill several small holes in the bottom. One hole for every 2-3 inches should be enough. If your child is using a Styrofoam tray, they’ll be able to poke holes into the bottom themselves.

Measure and cut lengths of the string for your wick. Cut a section for each hole in the bottom of your tray. When you measure, make sure the string is long enough to reach several inches into the water reservoir and up through the holes in the tray with a couple inches to spare. When in doubt, cut longer.

Steps:

  1. String the wick through the holes in the tray. For kids, it’s helpful to knot the wick with an inch or two of extra string in the tray.
  2. Fill the tray with your growing medium, and very lightly push it into place where needed.
  3. Fill your water reservoir with water and add your nutrient solution (plant food or fertilizer).
  4. Place the growing tray above the reservoir and make sure it’s sitting securely.
  5. Last, place your germinated seeds in the growing medium once they’re ready. Try to place the plants at least 2-3 inches apart, just like you did with the holes for the wick.

That’s it! Make sure you’re monitoring your plants, and that they’re staying healthy. This system really requires hardly any maintenance. When the water levels get lower, top off the water level.

What are the best kinds of plants to grow in this system?

The best kinds of plants to grow in wick systems are blessedly also some of the fastest growing (which is a boost to the excitement for kids). Greens, like lettuce and herbs (think basil, rosemary, thyme, spinach, etc) are the best suited for wick systems.

Deep Water Culture (DWC) system for kids

Suitable for ages: 8+ (with moderate to ample assistance), 12+ (with minimal assistance)

Assistance needed: minimal to ample depending on age

Difficulty: moderate

Materials needed: moderate

Cost: up to $35 (much less if recycled materials are used)

This system isn’t too hard for kids, but depending on their age they’ll need different levels of assistance. Since some electric parts are involved, you’ll need to take care of those steps for your kid (and educate them about electrical safety). You can grow a few plants in this system, depending on the size.  Here’s what you do to get this DWC system working:

Gather your materials:

  • Water reservoir (or plastic bin, tank, etc)
  • Board, tray, or Styrofoam slab (it should fit securely over the water container)
  • Netted pots
  • Seeds or saplings
  • Small aquarium pump and tubing
  • Airstone (easily found at pet stores in the fish section)
  • Plant food
  • Growing medium

Prep:

Start seeds or saplings, as referred to above.

If using a board or plastic tray, drill holes large enough to fit the netted pots through. If you’re using a softer plastic or Styrofoam this step is much easier.

Steps:

  1. Fill the netted pots with your growing medium (⅔ full is a good guideline), preferably over old newspapers or plastics bags to reduce mess.
  2. Fill your water reservoir with water and an appropriate amount of nutrient solution.
  3. Attach your airstone to one end of the tubing for the pump. Then attach the other end of the tubing to the pump (this should slip in easily to a specific circular port). Do not power on the pump yet.
  4. Place the airstone in the water reservoir (in the bottom and as near to the center as possible).  Most air stones come with suction cups that you can use to secure the airstone once you’ve positioned it.
  5. Once the airstone is placed, turn on the pump and ensure it’s working. You should see a steady stream of bubbles coming from the airstone. (Note: if the pump seems overpowered, or the airstone shifts despite being secured, valves with dial pressure adjustment are also available in the pet store for a couple bucks)
  6. Place your tray or board above the water reservoir.
  7. Place your netted pots into the holes you cut into the board during the prep stage.
  8. Make sure that the water level is high enough to saturate the netted pots. If it isn’t, add more water.
  9. Once everything else is set up, you can add your plants to the netted pots.

Once you’ve finished, you don’t have much maintenance to worry about. The nutrients will need to be replenished about every 2 to 3 weeks, and the water supply should be topped off when it visibly lowers. If the area you place the plants in isn’t very sunny, you can add supplemental lighting. If you’re in this situation, you can get one or two inexpensive LED growing lights and leave them on the plants during the day.

Note: If you do have to add extra lighting, make sure the lights are far enough from the plants that the plants don’t get dried, burned, or withered. Also make sure the lighting fixture isn’t going to get too hot throughout the day, as that can be a safety concern.

What kinds of plants can be grown in this DWC system?

Lettuce and herbs are an old favorite, but DWC systems give you more options. Yes, mint and basil are popular and quick growing, but older kids especially might like to see more ‘fruits’ of their labor. With proper support (like stakes or small lattice planks), you can grow tomatoes, okra, and even peppers that produce decent sized harvests.

Tips on materials for your system

Making a hydroponic system with your kid is a great way to spark their creativity by allowing them to find and gather materials with you. Items like the water reservoir and grow trays are often easier to find improvised materials for. Some other things might require a little ore footwork on your part, so here are a few tips to make it as easy as possible:

Use dollar store seed and seedling/sapling starter mixes: the bags are usually labeled “Bulb and Seed Starter,” or “Starter Potting Mix” (or something of that variety).  The point is, they usually contain a mix of vermiculite and perlite (so check the label just to be sure). The best part is that you get at least 12 to 16 oz of growing medium or more, for a dollar and tax.

Questions kids ask

Kids ask a lot of questions, and it’s no fun for anyone when you don’t have a solid answer. So just to get you a head start, here are some common questions that kids pop up with when you’re creating a hydroponic system (and an answer cheat sheet for you):

If we use growing medium, isn’t that the same as planting them in dirt?

While it looks similar, it’s pretty different. First, soil provides plants with nutrients. Growing medium does not (for older kids: it’s chemically inert, meaning it is inactive and does affect chemistry and sustenance of plants). Growing medium is basically there to hold plants in place and allow them to absorb moisture from the nutrient solution.

What’s the difference between the water and the nutrient solution?

Once you add the plant food (aka nutrients) to the water in your water tank (or reservoir), nothing. When you add the plant food to your water tank, it’s called often called nutrient solution.

Can we grow a tree inside now too?!

While neither of the systems we went over could grow a tree, larger hydroponic systems can. That being said, it would have to be a very large system, and a very small dwarf tree (these trees are smaller versions).

Can we put fish in here too?

Aquaponic systems do have fish in them. These hydroponic systems can’t support fish life if you’re adding chemical plant food. In an aquaponic system, you don’t add chemicals because the fish waste provides the plant food.

Are the plants drinking through the wick?

Kind of, but not really. The wick soaks up water, which the growing medium then soaks up from being close to, and touch the wick. The plant roots just absorb the moisture that’s pulled in by the growing medium.

Can we eat the plants?

As long as you’ve planted edible plants, yes. Since the plants don’t come into contact with chemicals, they’re especially healthy.

What’s the point? Plants grow in dirt, too.

There are a lot of ‘points’ of hydroponics. First, you can grow a lot more plants (food especially) for a lot less money. Growing plants in dirt also takes up a lot of space and water. With hydroponics you actually don’t use nearly as much water or space, so it’s good for the environment.

How long does it take?

It depends on the plants you decided to grow, but after germinating them most plants should have a decent amount of growth in 3-8 weeks (when you’ll be able to harvest them).

Hydroponic Equipment Explained: Beginners Guide to Everything!

Hydroponic equipment

Many people like the idea of having a hydroponic garden, although they may be unsure what equipment they need, or which is the best equipment for their garden. Either way, it is better they have a good understanding of all the equipment that will be required at some stage of their hydroponic journey.

Here is all of the major equipment and an overview of how they fit into hydroponic systems. Not all are required for every gardener, but it is good to know what options there are for equipment, and it can help when it comes to purchasing, and build time of a system.

Water Pumps

Water is the soul of any system, and without it, no plants would be able to survive. It is the function of the water pump to circulate water to the parts of the system where plants are located. There are a couple of methods which don’t need a water pump because of the way they work. These are deep water culture systems and wicking systems.

Both of these have a stationary reservoir where the plant roots take the nutrients directly from the water.

When you have a system which needs a pump, there are some differences which you can use to meet your needs.

Submersible

This sits directly inside the nutrient reservoir and is fully covered by the water. This type is the most common one in use because of a few different factors.

Submersible pumps are cheaper, quicker to install and use, and also they are quiet. The most significant downside of this type of pump is they generate heat, and this heat in some systems could make the mix too warm. This does depend on where the system is situated, and what the ambient temperature is like.

Another point to note is these pumps are not really suitable for much larger systems where there needs to be over 1200 gallons pumped per hour. GPH is a  measure of a submersible pumps power. These GPH’s are measured at different heights as it takes more energy for a pump to move water to higher elevations.

Inline Pumps

These differ to submersibles because they sit outside the water, and are more often used in Aquaponic systems or larger hydroponic systems such as commercial farms.

These pumps are not as easy to use as a submersible and are much noisier while being more expensive. These do have the benefits of having more power to pump water and will be more durable. Inline pumps also don’t generate as much heat that can pass into the reservoir. Inline pumps are also rated by their horsepower and not by how many gallons of water per hour they can move.

Water pump criteria

When choosing water pumps, there is a list of things you need to check. These are as follows:

Head height – this is the distance from the bottom of the reservoir to the height of water you wish to reach. This is why manufacturers give head heights so you can adjust table height of your pot height to fit. The maximum head height will be the water level which takes the maximum pressure to reach.

As finding the right pump from the measurements, can be difficult, it is advisable to choose a larger pump than you require. This also gives you the chance to expand your system with no need for a second pump.

Water pump efficiency should also be checked because not all pumps are as efficient as others. Check pumps at similar head heights, and the one who reads a higher number of gallons per hour means it is more efficient.

Air Pumps and Air Stones for Hydroponics Systems

After water, one of the most crucial elements for plants is oxygen. If water becomes stagnant, there is no oxygen, and your plants can drown. With air pumps and good air stones, you can diffuse air into the water. Another advantage is that these bubbles continually, mix your solution.

Like water pumps, it is crucial to have the right size air pump. As a guide, it is good to have a pump which delivers at least 500-600 cc per minute, although, even cheaper models are capable of producing this amount.

As air pumps on most occasions sit outside of the reservoir, they can produce a continual hum which becomes annoying. To find the quietest one, you can check the decibel levels that are supplied by manufacturers.

Although you may only have a small hydroponic system, it is still advisable to have an air pump which comes with multiple nozzles. This not only spreads air across your reservoir but if you have a multi- growing units, you can easily place an air stone in another tank without having to split your tubes.

One thing worth noting is your tubing. You may receive clear tubing, but this isn’t very good as light can seep into your reservoir where there is the chance of algae growth from moisture buildup.

When it comes to choosing your air stones, you are better having one that produces smaller bubbles. With these, there is a much larger surface area exposed to the water, and because of their smaller size, the bubbles will travel slower, so the water becomes even more oxygenated.

Hydroponic Reservoirs, Trays and Flood Tables

Reservoirs are vital, and depending on the type of system being run, these reservoirs are using in different manners. When growers purchase systems, these often come with a reservoir, however, these don’t allow for expansion, and this reservoir is matched to the system

A suitably sized reservoir will be required because there are some variables which need consideration. Humidity is one variable that is often overlooked. Plants like levels of around 60 – 80 percent humidity, and if this falls to 50 or even 40 percent, then this means plants need to take up more water and nutrients.

There is a simple formula you can follow for determining the size of the reservoir for your system. Here are the water requirements for each plant size:

  • Small plants – at least 1/2 gallon
  • Medium plants – at least 1 to 1 1/2 gallons for each plant
  • Large plants – at least 2 1/2 gallons for each plant

There are a lot of growers who err on the side of caution and double the amount of water their reservoir can hold.

Reservoir Considerations

  • Lids – a lid is essential to limit evaporation and also prevent algae growth. These lids do need to stop any light from entering into your nutrient mix.
  • Water temps – a range of 65 to 75 degrees should be maintained. A larger reservoir can hold its temperature more reliably compared to a smaller reservoir that might fluctuate in the nutrient mix.
  • Cleaning – regular cleaning is another way of preventing mold growth, or bacteria build up.

How Systems Use Reservoirs

DWC (Deep Water Culture)

In this system, the root tips are suspended into the water and nutrient mix inside the reservoir. They can receive oxygen from the oxygenated water and also from the space above the water to the bottom of the growing medium. In this system, if any light were to penetrate, the roots would stop growing due to air pruning.

Drip Systems

These feed from the top in drips, so the reservoir sits underneath. Your water pump delivers the water to the top of the pots where it makes its way to the roots before passing back through the container. All the excess runs back into the reservoir for recirculation.

Ebb and Flow (Flood and Drain)

A timer is used to control the pump which then floods a deep sided grow bed or flood table. After a specific period, the pump turns off, and the solution runs back into the reservoir. This reservoir usually sits below the grow bed.

NFT (Nutrient Film Technique)

A stream of nutrients are continually pumped around the system. This usually consists of tunes or channels where the plants are suspended. The root tips drag in this solution to receive nutrients and oxygen while the above roots are exposed to the air. For this system, there are no criteria for reservoir position as long as the exiting part of the pipe leads back to the reservoir. In this system, the water pump might not need to be powerful, but it does need to be reliable as it will be in operation 24 hours per day.

Wicking Systems

This is the most basic of all hydroponic systems. There is a section of fabric type material which sucks water (wicks) water into the growing medium. The roots will be continually fed from the moist growing medium. This system can significantly benefit from an air stone to prevent water stagnation. This method is more suited to smaller gardens, and many growers make these small systems using small net pots to hold the wick, and two buckets which sit inside each other. One to create the lower water reservoir, and a second to contain the growing media and the plants.

Grow Trays and Flood Tables

These are similar in construction and are made from durable plastic. Some are pre-drilled to allow water to drain back to the reservoir. The differences are usually in flood and drain systems where the sides are high enough to accommodate a substantial amount of water. When flooded, this soaks the growing medium before draining at the end of the timing cycle.

When used to build these flood and drain systems, they can be made very cheaply, and do require very little equipment, or experience to build and to run.

Shallower trays are ideal for seedlings and smaller plants as they are not able to accommodate large root systems. To a certain degree, even NFT uses a grow tray, but a very long one. These run-to-waste systems do differ from all other system types because the pipe where the plants sit is at a slight angle, all other systems in most cases are flat to ensure peak operation and efficiency.

Hydroponic Lighting System Basics

After water and oxygen, light is the next most crucial thing plants need to survive. For indoor growing systems, there are countless options available to growers. Rather than delving too far into what these types of light deliver, this will be a rough guide of the differences.

Lighting can be one of the hardest elements to control because each type of light delivers benefits, while coming with its own set of downsides.

One thing all new growers need to know is that any lighting system needs to replicate what the sun delivers through the seasons, and also for each stage of a plants growth.

Note: The size of an indoor growing space will dictate the type of lighting system, as will the variety of plants you are looking to grow.

HID (High-Intensity Discharge)

These fall under two sections and can be either Metal Halide (MH) or High-Pressure Sodium (HPS).

MH – Metal Halide Bulbs

These bulbs are used during the growth phase as they produce wavelengths which are toward the blue/ white end of the spectrum and simulate the hotter summer sun. Some plants such as herbs and more commonly leafy vegetables can reach maturity with just this type of bulb.

Many plants are able to flower under this light, but the yields you can obtain will be very much reduced, so they are commonly used in conjunction with HPS lights.

HPS – High-Pressure Sodium Bulbs 

The light wavelengths this produce are in the redder end of the spectrum, so these high pressure sodium lights have a reddish-orange tint which simulates the warmer colors of the harvesting period. These lights need using as soon as plants begin to flower.

This light combination is highly effective as it can replicate a full growing season for the majority of plants.

These lights can be cheap to purchase, but they do come with one significant downside. They produce lots of heat and use a lot of energy while running. With this information, two other areas come with these types of lights which will be discussed later. There are lighting hoods and ballast.

Fluorescent Lights

Fluorescent bulbs emit a cool light that is perfect for cuttings or seedlings and throws out low heat levels while delivering a wide angle of light. The smaller version, the CFL (Compact fluorescent lights) often comes in combinations of a few bulbs rather than just one. With this lighting system, the ballast comes as part of the system. This makes them ideal for growers who have smaller systems.

Another significant advantage is, these are very cost effective to run. While they might lack power when plants are more abundant, they are the only lights which are suitable for stimulation seedling growth.

LED Lighting Systems 

These lights are slowly gaining popularity, and although they cost significantly more than other lighting systems, to begin with, they are very energy efficient without the need to change bulbs for a good number of years.

LED lighting systems are cool in operation, so for small growing spaces, they will hardly affect the ambient temperature., and can be placed closer to the plants without the worry of drying them out or burning them.

LED’s can be purchased that produce different spectrums, or growers can buy multi-colored systems that cover all of the spectrum necessary for plant growth. This makes it more straightforward, and there is no need to change bulbs as with HID and HPS.

Sulphur Plasma

Just like LED lights, these are new to the world of hydroponics and can come with adjustable output. Ranges that they can operate can be from 100w up to 1300w, and what this means for growers is they can use them for multiple plant types in different sizes of grow rooms.

At present, the full effects of these lamps on hydroponic growing are not yet known, but their manufacturers are claiming they are highly energy efficient and can replicate natural light to a higher degree of accuracy as other lighting systems.

Ballast

While many growers use fluorescent bulbs, they will not see this component of hydroponic lighting systems as a separate unit. These do though play an integral role in lighting systems and making sure the lights function as they should. Their functions are:

  • To start the bulb
  • To control the flow of electricity through the lamp

Every gas-discharge bulb, regardless of the type needs this ballast to start. Fluorescent has a built-in unit which is usually a small round unit that twists into the side, while larger lights require a separate unit.

Ballast comes in two varieties, and are either electronic or magnetic.

Magnetic is the most basic and use a coil around a core to deliver the minimum required electric to start the bulb. This is why lights flicker when starting, or the buzzing sound you can hear as they are running.

Electronic ballasts use PCB’s and deliver many more benefits over magnetic. They are smaller, quieter and are more efficient. This allows them to pass a consistent flow of electricity through the bulb. Additionally to this, this kind of ballast can be sued to control multiple bulbs.

Lighting Hoods

Many growers have their favorite grow light reflectors, this can be because of price, so may look cool, or some outperform other designs altogether.

There are a few types of reflectors, but in essence, they are there to reflect light onto your plants. Here is a quick run through of the models.

  • Wing reflectors – one of the more popular because they deliver a wide spread of light, although still focused.
  • Umbrellas – these are not able to penetrate deep inside plants leaves to deliver light. They do however fill many gaps that your other lights can’t reach. They are often used as supplemental lighting systems.
  • Hood reflectors – these deliver the best intensity out of any reflector. This means your plants can receive the very best light possible. There are two types you can choose wide and squat, or the other option narrow but tall.
  • Air cooled reflectors – bulbs will generate a lot of heat, but this can be reduced by using air cooled reflectors. It also has the benefit of keeping your growing area cooler as the lights have little effect on warming the air.

Grow Room Ventilation

There are two factors when it comes to growing room ventilation because circulating air isn’t sufficient. This is because plants which are grown in an outdoor environment are continually blown by the wind. This helps the stems become stronger, and as a result, plants grow stronger.

When air is only circulated, this does nothing to rid a growing space of humidity and moisture, and as a result, it can be the ideal conditions for mold or algae growth. Although oscillating fans are required, a grow room does need fresh air carried into the area.

This outside ventilation reduces the risk of mold, spider mites, and other pests and disease. All this is on top of plants growing much stronger. Grow rooms need a combination of both oscillating fans and external ventilation to bring in fresh air while the old air is expelled.

These systems are often seen in indoor grow tents where there are both inlet and outlet vents to perform this air exchange, and there is an oscillating fan to help circuit the air and buffet the plants. Fans are measured by CFM (Cubic Foot Per Minute), and to calculate what you need, you must use the size of your grow room and the exhaust efficiency of your ventilation system.

There is a quick formula to calculate this:

Grow room length x width x height = volume

Exhaust efficiency takes into account the length of ducting from the fan to the filter. Next, you multiply the volume of your grow room by 25%. Many growers make a much easier calculation and multiply the volume by two for short ducting, or by three for longer ducting.

This gives you the cubic foot per minute, so you need a fan which delivers a higher CFM than your result.

Climate Control

This might not be something a small grower controls using these methods, and to some extent, this can be carried out by the ventilation as mentioned earlier. When gardens start using heat-generating light combinations, both the mix of nutrients and the humidity need controlling. On top of this, there are regional conditions to consider, because some climates are too hot even before any lights are used.

For larger gardens, some growers use automated systems to keep their grow rooms at the ideal temperatures and humidity. Although these are more common in commercial hydroponic farms, there are cut down versions that are ideal for smaller contained gardens.

The more basic models monitor and control one aspect of the grow rooms environment, such as temperature. At the other end of the scale are the electronic control systems which monitor all variables such as temperature, humidity and CO2 (Carbon Dioxide). When these are in operation, they will control all the fans, ventilation, air conditioners, dehumidifiers and many other pieces of equipment.

As useful as these systems are, there is no replacement for fully understanding how all these variables affect your plants, and how you can control them manually.

Indoor Grow Tents

Hydroponic system gardens can be split into two avenues. There are the growers who utilize spare space to set up a system and run it as is. There is also the second group of people who want to create an ideal environment for their plants.

These are the ones who opt for using an indoor grow tent. These do come with benefits, and one of the first is plants are being grown in a controllable microenvironment. Many suppliers sell indoor grow tents as kits. These will include all of the above elements and can be a great way for growers to get started.

These ready-made environments will have the right levels of air ventilation, lighting and grow beds, as well as the correct sized reservoir. But, there are significant numbers of growers who are keener on constructing their own hydroponic system rather than relying on a kit from a supplier.

Additional Components

Aside from these larger components, there are many other smaller ones which are as crucial. Nutrients, growing medium, starter plugs, thermometers, and digital pH testers and chemical adjusters all play their place, and without many of these, your garden will fail.

Conclusion

Out of all of the above equipment, there are cheap versions and the more expensive versions. Many growers may never use some of the above parts, but it is still worthy to see what is available in case a grower has a hydroponic system they want to expand.

It is also like the grow kits which can be quickly erected in a spare room or basement. Many growers want to pick and choose their components, so they know what they are dealing with. In some cases, this could be the more difficult approach, but when growers want the best for their plants, they don’t want to rely on a readymade kit, that is promising certain degrees of success.

Some of the fun for the more adventurous growers is choosing your own equipment. It can cost a little more, but in the end, you will be able to reap the benefits of learning about every little detail.

How to Set Up a Hydroponics System: The Fundamentals

Basics of Hydroponics

Many people have either just started with a Hydroponic garden or are looking into starting one. Although there are vast amounts of information available, many sources don’t cater to new growers when it comes down to the fundamentals of running or building a hydroponic system.

There are many types of systems users can use, but these core fundamentals remain the same no matter which system is being used.

Here we will take a look at each section in turn and see how it reflects on your system, or how it can affect your decision on which system you wish to build. Before diving into the core fundamentals, we will give a rundown of the most common types of hydroponic systems people choose to run. These can be purchased or bought, and it doesn’t matter how the system is built, the end result will be the same.

Types of Hydroponic Systems

With all these systems, we will look at what they comprise without mentioning nutrients or pH kits because these will be standard across all systems.

Kratky System

Difficulty: Beginner

This is one of the simplest methods of hydroponics available and requires no electricity. All this needs is a dark container with a lid, net pots, and your growing media. These are suitable to grow spinach, lettuce, tomatoes and many other leafy types of vegetables.

In the lid will be the holes where to place your net pots. Once they are filled with your growing media, the young roots will protrude from the bottom of the net pot into the solution. As they absorb nutrients, the level drops and the roots grow. At this point, the space in the top of the container delivers oxygen to the roots.

DWC (Deep Water Culture)

Difficulty: Beginner

A DWC system is very similar to the Kratky system but on a larger scale. This system only requires an aerator pump and can cater to a more significant number of plants. In this system, the water continually bubbles to deliver oxygen to the plant’s roots.

Flood and Drain (Ebb & Flow)

Difficulty: Intermediate

This is one of the most popular hydroponic systems in use, and for a good reason, it can produce some of the best results out all the systems while being easy to maintain. Here the plants will be grown in any suitable growing media inside pots. These are then spaced in a grow bed which is a little higher around the sides than the containers.

The nutrient reservoir will be a separate unit that is large enough to hold enough nutrient solution to flood the grow bed. In the grow bed, there is an overflow pipe that will stop water rising above the height of the pots. Next, you will need a water pump which is used at intervals to flood the grow bed, once the timer finishes (15 or 30 minutes at intervals) the water flows back through the pump into the reservoir.

Plants receive enough water, and oxygen once the grow bed drains. The addition of air stones will deliver more oxygen to the roots which lead to healthier plants.

NFT (Nutrient Film Technique)

Difficulty: Advanced

These systems are an all in one solution. In most cases they contain large 4-inch PVC pipes that have holes cut into them which will hold your net pots, again these are filled with your growing media, and the roots protrude into the bottom of the pipe.

The reservoir will hold the pump and air stones, which continually flows down the pipes and returns back to the reservoir. Roots are still exposed to the air to receive oxygen so they won’t become overwatered. The weak area of this is when there is a pump failure. Plants can quickly suffer because their growing medium won’t be holding sufficient moisture to maintain the plants for extended periods.

Drip Systems

Difficulty: Intermediate

In this system, each plant will be fed individually. What differs in this kind of system is the plants are drip fed from above whereas all other systems are fed from below. There is still a separate reservoir that contains both the water pump and aerator stone, and from the pump, there are small diameter tubes that feed the pots on a timed period. The nutrient then drips from the bottom of the pot or container back to the reservoir.

In design, it is very similar to a flood and drain system, but without the flooding aspect.

There is one other system called aeroponics which differs to all of these because a fine mist of nutrients is sprayed onto the roots. These can be much harder to set up, and might not deliver as many plants in your growing space. Additionally, many of these systems are purchased rather than being built.

 

A Look at Hydroponic Fundamentals

We will now take a look at the fundamentals of hydroponics. These will contain seen before information and will be general across all systems.

There might be problems with one system more than another, but the ways to solve these will be the same. As an example, if you have waterlogged roots, then the solution will be the same regardless of the system. All that differs in hydroponic systems is the nutrient delivery method and the ease of operation.

Light

Germination requires very different rules when it comes to growing in a hydroponic system so they will have their own section. But, once plants are transplanted, they do light which is the most essential ingredient for plant growth.

It doesn’t matter if you have your system in an outdoor location, or an indoor grow room, without light, and sufficient amounts of it, your plants won’t survive. The purpose of light is to induce photosynthesis where carbon dioxide and water become converted into plant food and oxygen. So, the more light your plants receive, the faster and more bountiful they will grow.

There is one worthy mention, and that is if growing indoors under artificial light, you can obtain better results than if plants were being grown in a sunny window. This is because you are controlling the amount of light compared to variable light throughout the day.

Sunlight varies throughout the year, so even if your plants are in a warm enough environment, their growth will still change throughout the seasons.

When using grow lights, the one thing you must ensure is plants receive the full spectrum of light. This needs to be from the bluer end of the spectrum all the way to the other where there is an abundance of red light.

When using grow lights, there are countless types and strengths that growers choose. You can choose from fluorescent, LED’s, High-pressure sodium or metal halide bulbs. All these come with unique benefits and downsides.

What is crucial is that no matter which bulb you use, they all governed by the following three factors:

CCT (Correlated Color Temperature)

This is expressed by using a Kelvin scale and will relate to the temperature of the light source. This doesn’t necessarily mean one bulb is hotter than the other to the touch. It is the warmth of light that is measured.

A good example is 6000 Kelvin is recognized as being cool light, and a light source which has a CCT (Kelvin) of 2700 would be considered warm.

 Wattage

A grow lights watt usage is how much energy it will use when it is turned on. This also has a relation to how bright it will be because of the electric running through the element.

A regular light bulb in the home uses about 75 watts. But, in some hydroponic grow rooms, there are lights of 250, 600 up to a 1,000-watt bulb being used. At this level, they will use the same electricity as you’re A/C or other larger electrical device.

The downside to most of these HID lamps is they need changing periodically:

  • 24 hours per day – change after 6 months
  • 18 hours per day – change after 9 months
  • 12 hours per day – change annually

Lumens

This is how much light per square foot that will be emitted by your grow light bulbs. This measure will be dictated by the manufacturer and not the power consumption (wattage). High numbers of lumens equate to high-quality lights. Never opt for a bulb which delivers less than 2,500 lumens. You can also use the 20 – 50 watts calculation for each square foot of your growing area.

With all this, it is fundamental that you provide your plants with at least 14 – 16 hours of good light each day.

Air

There are a few factors that are included under air, these will be humidity, temperature and carbon dioxide. All these are important for any hydroponic system and can have a severe impact if they are not in the right region, or the correct levels are not met.

Carbon dioxide is produced by every breath we exhale, and to a certain extent, there are levels in the air we breathe in. In outdoor gardens, these levels are controlled without too much intervention, but for an indoor garden, this can be very different.

Air ventilation, rather than only having airflow is crucial because the levels of CO2 might only reach around 400 ppm (parts per million). Levels required should be up to approximately 1,500 ppm, and without supplementing this unnaturally, it will need fresh air to be entering your grow room.

You can see how some growers control this by using grow tents, this reduces the space, so the ppm of CO2 increases. These tents will have an exhaust fan, and fan on the other side which blows in the fresh air.

After this, we come to the ambient temperature. This can change depending on your plants. However, almost all plants are unable to survive for too long outside their ideal growing temperatures. This can be either up or down, so growers shouldn’t think just because they are indoors that it doesn’t become too cold.

This is another area that is affected by an influx of fresh air from a ventilation system, and also from any grow lights which are in operation. The ambient temperature of the air does need careful monitoring and adjustment.

The next area affected by the air is humidity. Some plants are very choosy about humidity levels. When humidity is too high, it becomes ideal for mold or algae, and this is especially true in your reservoir. Low humidity on the other end, can stress plants as it struggles to replace moisture.

Water and Hydroponic Nutrients

Every system has different requirements. These can be because of the grower or the plants being grown. Many growers choose already mixed nutrients, and merely adding these in varying quantities is enough for many people.

There is though, an underlying element to this which is fundamental for successful growth which growers should be aware of. Purchasing a bottle of nutrients is straightforward, but knowing what they do is very different.

Knowing how these elements work, it is handy to see how commercial growers use their powdered compounds to achieve their desired results.

NPK is what all grower know what they need to follow for maximum growth of their plants. These come in different solutions such as 20-10-5. This means there is 20% Nitrogen, 10% Phosphorous and 5% Potassium.

When plants reach later growth, they should be receiving lower amounts of N (Nitrogen), this is why some larger scale commercial growers mix their own, they are in a far better position to control each compound as necessary.

One thing to note here reflects back to the temperature of your grow room. You might need higher amounts on N (Nitrogen) if the temperature is under 80F when your plants are in their vegetative growth phases. If your grow room has a temperature that is higher than this 80F, then you don’t need to adjust the N levels.

There are lots of NPK ratios you can see, but not all will be right for your garden. Here is a guideline that can be used as a starting point:

N (Nitrogen) – 200 – 400, P (Phosphorous) – 200 – 600, and K (Potassium) 200 – 600

On occasion, plants might suffer from magnesium deficiency. The addition of Epsom salts to your water is an easy remedy for this. No matter how you obtain your nutrients, and this can be dry or liquid, but the one fundamental thing is to never over-feed your plants. It is much better to slightly underfeed and add rather trying to reduce.

When we look at nutrients and water, there is the temperature to consider, and if your mix is too warm, this can lead to bacterial growth. Other areas which need consideration and are fundamental to successful plant growth are:

  • EC (Electric Conductivity)
  • CF (Conductivity Factor)
  • TDS (Total Dissolved Salts)
  • pH Levels

When you look at your TDS levels, these are ideal when they fall in the range of 500 – 1000ppm in your solution. When there is a reduction in the ppm plants can take up nutrients easier. This is true in younger plants or seedlings, and once they reach their vegetative growth phase, these levels can be increased to 800 – 900ppm. This will equate to a stronger nutrient solution.

Once plants reach their maturity or flowering phase, these TDS levels can be further increased to 1000ppm – 1100ppm before being reduced in the final phase.

No matter what levels you are using, these TDS levels should be measured along with pH levels on a continual basis. EC meters test the conductivity of your solution and will determine the TDS which is the level of dissolved salts.

We all know pH levels need to be measured on a routine basis. These work in conjunction with the strength of your solution because they will change as you add nutrients, or add new water to your reservoir. Ignoring these or leaving them too long before checking can have a dramatic effect on your plants.

One fundamental factor is to never mix either pH UP, or pH Down into your nutrient mix. The chemical components can produce a chemical reaction. Such is the risk of this, you should only use one dropper for each chemical. Water should be checked adjusted before it is added to your reservoir, this way you can adjust without shocking your plants with a dramatic rise or fall of the pH level.

To make sure your nutrients don’t become too strong, you can top up (top off) your reservoir with half strength of nutrients to what you first began with. This should be done every other day, and the days in between, you can top up with plain water (pH checked).

Changing Nutrients and Flushing Reservoir

This will be one of the most fundamental things a grower needs to do for their system. But, there are two ways that different growers use to calculate when to do this. One uses a time-based approach, and the second uses the volume-based approach. This is where the above TDS levels come into play.

Here are the two different approaches to doing this:

Time-based

This can be between 10 – 14 days for small hydroponic systems. It required all of your old nutrient mixes to be disposed of and refilled with a new solution. Larger systems can be stretched to one month before changing the solution. Out of the two, this is the recommended way of gauging when to change.

Volume-based flushing

Using the above TDS and EC readings, the time to flush the system is when youhave used half the starting amount. With this way, many people top off their tanks as nutrients are absorbed. This requires continual monitoring, as soon as the top off amount reaches half of the original starting volume, then it is time to flush the system.

Growing Mediums and Water Quality

A growing medium adds nothing to a hydroponic system in the way of nutrients. There the only function is to deliver support for your plants. There are many of these growing mediums which are suitable, and on occasions, a grower will use more than one type.

Many growing mediums must be thoroughly soaked before use. This is the case for Rockwool when germinating, but also vital when used in a full system. It is crucial to use the best growing medium for the plants you grow and the type of system you are using. A good example being coco coir. In systems which utilize water pumps, the fibers can start blocking the pump, but in DWC or NFT they have less chance of easily being passed around your system.

When using water for your hydroponic system, this needs to be clean, so there are no bacterial elements contained in it. This is why growers use pure or reverse osmosis water. It also means they have a clean slate when it comes to adding their nutrients.

If you see deposit buildups around your faucets, this means you have hard water. If this is the case, it means you have too many minerals. If you use this kind of water and it has a TDS of over 200ppm, you will need to adjust to allow for this difference because it will affect your TDS with nutrients added. Again, this is the reason clean water is used.

We have seen it is crucial to keep your nutrient mix at a certain temperature. However, it should be noted that optimum root growth will happen when your mix is between 70 – 75F, but if you have any root diseases, these grow faster in these conditions.

If you maintain a temperature under 68F, it can go a long way to helping prevent root rot in your plants.

Additionally, it is harder to regulate the temperatures in both DWC and other ‘Bubbler’ systems because there isn’t usually an external reservoir and the small water volumes. One other point of note that is very often overlooked is that aquarium pumps can run hot, so they do add heat to your nutrient mix.

Fundamental Do’s and Don’ts for Your Hydroponics System

We know that there are some varieties of plants which don’t grow very well in hydroponic systems. Many root crops are not as successful as leafy vegetables because of the way growing media works compared to soil.

There are as we said many fundamentals which need adhering to, as well as a handful of things you should do, and things you shouldn’t. These can be seen here:

Do’s

  • Light exposure to your reservoir should be limited to when you are topping off your solution. All pipes leading to growing beds should be dark to prevent light exposure and every possible way light can seep through your cover should be capped.
  • Clean supply and drain lines on a regular basis. This can be every few days depending on the type of system you use.
  • Pumps lose efficiency over time, check these to make sure they are pumping as they should. Flood and drain systems especially.
  • Clean filters if they begin clogging. Coco coir can cause blockages here.
  • If you use reusable growing media, wash it before re-use and allow it to dry.
  • Carry out thorough sterilization of media and pots and any other components between growing cycles.
  • Sanitize your components and system daily.
  • Do always check your pH levels. Even if you use a litmus strip for a quick check, you can quickly see if there are any changes.

Don’ts

  • Never use lemon juice
  • Never use liquid bleach in your system
  • Never add iron while any UV is running. This can lead to chelates being created. Any UV should be turned off until the system has cycled.
  • Don’t let your growing media remain wet, this will lead to root rot. Time your cycles, so the growing media is almost dry before the next feeding cycle.
  • Never use a water softener to treat hard water. These add salts to the water that are harmful to plants.
  • Don’t let your nutrient mix rise above 75F or fall below 50F. You might need an aquarium heater or chiller to compensate. Air stones can be used to help cooling as long as they are using external air.
  • Don’t place grow lights too close to your plants. If you have no option, point an oscillating fan to where the hottest areas will be.

Conclusion

As you can see, there are a few things you need to keep an eye on or consider when setting up a hydroponic system. With the basics of your water and nutrients, the effect of lighting, and ventilation, you will cover almost everything.

Some of this will depend on your grow space, and if you have access to external windows or it is sealed off, and you are wholly reliant on grow lights. Once you have these basic fundamentals under control, you are in a position to take on any hydroponic system because the same basic rules will be the same.

Once you learn the basics, you can quickly extend any system or build a larger one from scratch. A lot of the fun is in discovering new tips and techniques, but these fundamentals will never change.

A Brief History of Hydroponics

Brief History of Hydroponics

Our ideas of modern hydroponics vary greatly, depending on how you ask. For a lot of people however, they’re thinking of hydroponics as a modern technology (likely thanks in part, to NASA’s use of it to test growing in space). The truth of the matter is though, that hydroponics is no new player to the game. Yes, we’ve done a lot of innovating since the very beginnings of hydroponics, but that tends to happen over thousands of years. To really appreciate the legacy that our modern hydroponics come from, we should look at the history of hydroponics. At least, briefly.

It’s got roots in ancient legends

The legendary hanging gardens of Babylon were said to have existed around 500 B.C.E. Created by King Nebuchadnezzar II as a gift to his wife Amyitis, the hanging gardens of Babylon were one of the seven ancient wonders of the world. Scholars and archaeologists have long studied the intricate watering systems that supported the massive gardens. With elaborately tiered stones holding the plants, water was delivered through a consistent flow from central water reservoirs. The plants were kept fed and supplied with plenty of aeration through the consistent flow of water to their roots.

Greek historians have described the legendary gardens saying:

Streams of water emerging from elevated sources flow on inclined channels. These waters irrigate the whole garden saturating the roots of the plants, keeping all the area wet. Thus, the grass is permanently green and the leaves of the trees grow firmly attached to flexible branches.”

While we ought to put in the disclaimer that these hanging gardens are, as of yet, the stuff of legends without a solid archaeological discovery, they’ve been well documented by historians. And to even the novice hydroponic gardener, the quote above is a pretty obvious description of hydroponic methods.   

The Ancient Far East

For nearly as long as rice has been a harvested crop in Asia, it has been growing hydroponically. The image you’re probably conjuring in your mind is of the massive rice paddies that are concentrated around China. To be fair, that’s a pretty accurate assessment. While things like scale, spacing, harvesting, and other lesser details may have changed, it’s not by much. The main process for growing the rice remains the same.

At the very onset of rice farming, there were attempts the grow rice in soil. While this was more difficult, rice as a crop showed itself to be a valid investment. After significant seasonal flooding, many other sustenance crops were destroyed. Rice, however not only withstood the watery conditions, it thrived. This was the spark that lit the fire that blazes in hydroponic rice farming to this day.  After this revelation, rice was intentionally grown in organized water systems. Not only did the rice grow better, it resisted more disease and pests than other crops, as an added benefit to its hydroponic placement.

We have further documentation that the use of hydroponics continued, and further developed in China. When Marco Polo recorded his travels in the 13th century, China had taken hydroponics from being used for rice farming only to being used for aesthetic pleasure too. Polo described ‘floating gardens’ that floated in water on platforms. 

It’s also worth mentioning that while rice fields were used for hydroponic harvests, they actually ended up providing more diverse food sources as well. Today, we use the term ‘aquaponics’ to refer to hydroponic systems wherein fish are also held, sometimes in commercial settings for fish farming. In Indochina and China, a similar system was established. Fish were raised and farmed in the flooded rice paddies already in use for crop production.

Related: How does aquaponics work?

Modern aquaponics operates with the same similar principles historically used in the rice fields, but with a bit more nuance, and a lot more technology. Basically, where a typical hydroponic system has a reservoir to hold nutrient solution, an aquaponic system has a fish tank. A pump moves the water up to the grow tray, or plant bed. Excess water is filtered through by the plant roots (making it safe for fish again) and returned to the tank. The fish waste then provides nutrients to the water, which is then delivered back to the plants above.

Hydroponics in the pyramids?

It’s not as well known, but that doesn’t make it any less true. The ancient Egyptians used hydroponic methods to grow crops as early as several hundred years B.C.E. Archaeologists have found documented proof of this in records detailing the methods and uses of these early hydroponic methods relying on the Nile.

So sadly, our visions of hydroponic pyramids aren’t accurate. But hieroglyphs have been found that tell us the story of an innovative people using the flooding Nile River to grow crops without soil.

Tiberius

Archaeologists can confirmed that hydroponics have been used in Rome as early as the first century C.E. The Roman Emperor Tiberius, for all his other transgressions, was the first (that we’re aware of) to successfully use more complex hydroponics in this part of the world. And while it wasn’t used widely to grow crops, he did get to enjoy some cucumbers out of season.

The Romans described the plants as growing through ‘clear stone’ and being watered for sustenance. While we may not know exactly what this ‘clear stone’ was, it was certainly their form of a growing aid. While it’s been debated what the translucent stone actually was, some people think it was a form of growing medium.

The reality is (as strange as it is to think about) that this translucent stone was mostly likely an early form of a greenhouse. By using a clear material (like stone or glass), the off season cucumbers would have gotten ample sunlight, heat, and retained humidity.

The Aztecs

Another notable civilization that employed the use of hydroponics was the Aztecs. They developed an impressively well designed hydroponic system that successfully provided their people with plentiful crop harvests. Their use of hydroponics was developed out of necessity due to their nomadic culture and their situation within swampy, marshy lands. In these regions, it simply wasn’t possible to farm traditionally because there was very little, if any suitable land.

The Aztec hydroponic system is akin to what we might picture as a floating raft farm. By creating dense rafts from reeds and rushes secured with tough dried roots, they were able to float crops in the canals around their settlements. Rather than fields, they had canals full of thriving crops and gardens. To secure plants to the rafts they dredged up nutrient rich silt from the river or canal’s bottom, while plant roots pushed through the bottom of the rafts to reach the water below.

These rafts were called Chinampas. These Chinampas were so well developed that they never sank despite heavy crop growth (and even growing trees hydroponically on the rafts). 

The best comparison we can make between the Chinampas and the hydroponic systems we’re familiar with today is DWC, or deep water culture, systems.

Related: How do Deep Water Culture systems work?

Deep water culture systems keep plants in growing trays or platforms that allow the roots the hang beneath and into a nutrient solution below. To maintain adequate aeration, DWC systems often use an additional air pump or airstone. Typically roots are held in netted pots that are submerged in the nutrient solution.

Onset of modern hydroponic development

The long used hydroponic systems among other civilizations didn’t go without notice from foreign explorers. From Spanish Conquistadors in Mesoamerica, to Christopher Columbus’ recollections of his visits to China, the use of hydroponic systems were well documented.

What we may consider more modern hydroponics really began with the first attempts to understand hydroponics in an analytical, scientific manner. While we can debate what constitutes ‘modern hydroponics’ for days, let’s err on the side of simplicity. So, in the interested of avoiding a wormhole debate, we’ll say ancient hydroponics was achieved and used, but not analyzed on a quantifiable, scientific method. Likewise, we’ll say modern hydroponics began as we began to measure, analyze, and modify existing hydroponic systems. 

It’s worth noting that often various scientists, agriculturists, and other innovators came to similar revelations about plant growth, physiology, and hydroponics, although at different times and to varying specifications. Keeping that in mind, note that mentions of discoveries that were repeated or ‘rediscovered’ aren’t in error, they’re simply a result of our ebbing and flowing development.

Early ideas that supported hydroponics

The master inventor and artist Leonardo da Vinci, like many of his innovations, was ahead of his time in his revelations about plant growth. While the French king Francis I had da Vinci in his employment, the inventor progressed his studies in agriculture. Ultimately he determined that plants need minerals to grow, which they absorb from the soil. Notably, he realized that this occurs only with the help of water, the absence of which prevented any nutrient absorption.

While it was another couple hundred years before more modern scientists picked up on his discoveries, we’d be remiss to neglect giving him credit. He detailed the strong importance of irrigation, and effectively laid out some of the very basic principles that govern hydroponics today. Mineral absorption through water, the importance of irrigation, and the idea of doing away with soil and delivering minerals through water, are just some of the things we can credit to him. 

Main developments in hydroponics 1600’s to 1800 C.E.

Starting in the 1600’s, people began to attempt to create methods of protecting crops from weather and increase their harvesting capabilities. While these developing techniques weren’t strictly hydroponic, they did signal the beginning of an increasing interest in developing more advanced methods of harvesting crops.

Sir Francis Bacon takes the title for the first ‘modern’ published book concerning growing plants in a soilless environment. The book itself was Sylva Sylvarum and sadly wasn’t published until the year following his death, 1627. We can rightfully thank Sir Francis Bacon for the growing popularity of hydroponic research that began thereafter. So, thank you Sir Francis Bacon.

The next major revelation of hydroponics didn’t happen again until 1699. At this point John Woodward had been experimenting with growing spearmint in soilless culture. When he published his experiments, he noted that the plants grew better in less pure water (rather than the distilled water he also attempted to use).

The next century passed without much innovation specific to hydroponics. That being said, the 1700’s did bring the invention of manure heated greenhouses, which helped push along the influx of heated greenhouses (which can be compared to the heated hydroponic systems commonly seen today).

19th century developments

After a couple centuries of what we can call ‘simple’ attempts to understand different aspects of hydroponics, scientists were starting to get it (or at least they were on to something). We can credit the 1800’s with a lot of discoveries that led the way to further developing hydroponics.

By about 1842 they had created a list of 9 nutrients that they believed were necessary to sustain plant life. While it wasn’t perfect by any means, they weren’t too far off. Having realized that by adding minerals and nutrients (in this case they simply said ‘elements’), they could add these to the plants’ water supplies and progress to soilless crop growth.

By 1851, this list of 9 elements essential to plant growth had been more or less confirmed by Jean Baptiste Boussingault. We can also attribute much of the development of what we call ‘growing mediums’ to his research. He used inert, soil-like materials to place plants in, such as charcoal, pure sand, and quartz. Boussingault then nourished the plants with chemical solutions he recorded. Water was needed, that was a given. But in his work he was pretty close to the mark with the other nutrients needed: namely, Nitrogen.

He then started work on the ratios of the minerals needed. If you’ve ever had to purchase nutrient solutions for your hydroponic system, this should sound very familiar (think of the N-P-K ratios on every container).

Beyond the realization that nutrients needed to be added, there weren’t a whole lot of other leaps in the study of hydroponics (at least as far as the 1800s are concerned). However, this revelation was a critical foundation for the continued development of better plant food, much like the hydroponic fertilizers we use today.  

Early 20th century developments

While ‘hydroponics’ is a household term today, it was only relatively recently that this ‘soilless culture’ got the title it uses now. In the 1920’s William Gericke, a professor at the University of California in Berkeley began promoting soilless crop growth and later coined the term ‘hydroponic.’ While he initially tried calling it ‘aquaculture,’ he soon discovered that the term was already being used to refer to the culture of aquatic creatures and organisms. Thus, he settled on hydroponic.

The term comes from Greek roots:

Hydro: “water”

and

Ponos: “labor”

Gericke created something of an early PR opportunity for hydroponics when he appeared with vertically grown tomato plants in his new nutrient solution culture. Here’s the real kicker:

His tomato plants grew a whopping 25 feet tall.

From 1925 to 1935 there was an increased interest in plant physiology and enhancing techniques for crop growth. While greenhouses were established (and even experienced an early introduction to hydroponics with the use of gravel culture over soil culture), they were just plain expensive and didn’t catch on much. That’s because the growing beds were still being constructed of concrete, and that got costly.

However, expenses of food production also nudged hydroponics onto the world stage. Transporting food to troops overseas during the second World War was also a financial burden. Rather than creating a shift away from hydroponics, it actually prompted the widespread use of hydroponics throughout the Pacific and South Atlantic. This in turn increased hydroponics’ overall popularity, and created a solution that provided economically grown crops to the troops stationed there.

In 1938, Gericke’s work on soilless culture was expanded by two scientists also hailing from the UC Berkeley. Daniel Arnon and Dennis Hoagland were the two to take up the cause, and they ended up publishing one of the cornerstone documents of hydroponics. Their work, The Water Culture Method for Growing Plants Without Soil, is generally considered one of the most important publications to the development of hydroponics. They detailed the process and included formulations for nutrient solutions, now called Hoagland solutions, that are still widely used today.

This ultimately resulted in one of the first major commercial hydroponic operations. Wake Island, a typical stopover and refueling point for Pan-Am Airways, was used as the staging area for this operation. They were able to successfully grow vegetable hydroponically, which in turn was used to feed the Pan-Am airline workers.

Growing into greenhouses

Greenhouses experienced a significant boost in the 1950’s thanks to the developing proliferation of plastic and all its uses. Just like you see in greenhouses, plant factories, and home hydroponic systems today, plastic became a staple material in constructing these plant habitats.

Previously the heavy, expensive materials used like glass in concrete prevented much development in greenhouses, and as a result, the hydroponic systems housed therein. This newer, cheaper material (plastic, of course) made way for a lot of innovation to come. Because of the dynamic uses of plastic, new and essential components for hydroponic systems. This allowed for drip systems, improved irrigation, filters, water reservoirs, among other innovations to be introduced.

Thanks to this new accessibility and reduced cost, there was a sort of boom in hydroponics’ popularity. Ultimately, this ended up with an influx of investment into large, commercial hydroponic systems. 

As it happened, the influx of plastic and greenhouse systems also cleared the way for drip irrigation. Today, drip systems are still a common type of hydroponic set up because of their ease of use, effectiveness, and inexpensive needs.

Related: What exactly is drip irrigation, and what is a hydroponic drip system?

Drip irrigation isn’t limited to hydroponics. In fact, it’s a common method of irrigating soil grown crops too. Basically, tubes or pipes deliver smaller amounts of water and nutrients (or ‘drips’) to plants close to their roots. The delivery tubes usually have small holes placed at specific intervals to reach each individual plant. In hydroponic drip systems, it works exactly the same way, although the placement of drips and plants may be slightly different.

Later 20th century developments

In the 1960’s, we finally see the development of more specific hydroponic system types. The first that appeared was the Nutrient Film Technique, developed in England by Allan Cooper.

Related: What is Nutrient Film Technique (NFT)?

Briefly, Nutrient Film Technique type systems use a growing tray with channels where the roots of plants sit. The tray is placed at a slight angle while water saturated with nutrient solution flows across the roots continuously, providing both nutrition and aeration. The excess runoff water is then deposited back into the reservoir where it is pumped back into the root channels.

By 1978 the public had a resource to understand and implement hydroponic systems of their own: the book Hydroponics Food Production was published by Dr. Howard Resh, an early hydroponics pioneer. Thanks to this publication, we can credit the use of the staple 3 ratio nutrient solution (Nitrogen-Phosphorus-K potassium) that we still use today.

By the 1990’s NASA started research using aeroponics as a more efficient method of growing plants in space. By 1996 a researched by the name of Richard Stoner began getting funding from NASA to further continue his research of aeroponics in pursuit of crop production in space. In the following years, 1998 and 1999, their research focused tightly on developing an effective aeroponic system that would work with zero gravity. They ended up designing a functioning, self contained aeroponic system that could be used in colonizing space. 

Related: What is aeroponics?

Aeroponics is a form of hydroponics, although sometimes people mistakenly refer to them as entirely different things. Aeroponics still relies on the use of water only to deliver nutrients. The difference from other hydroponic systems is that aeroponics delivers water in very fine mist droplets that spray more frequently (or constantly in some systems), and no growing medium is ever used. The fine mist reaches roots and provides an efficient delivery of nutrients without the need to worry about extra aeration.

Contemporary hydroponics

All of the history that built hydroponics into various civilizations is the foundation of our contemporary hydroponics today. Hydroponics began as a simplified process compared to what it can be today. That being said, the main functions of hydroponics aren’t so very different from their ancient origins. The founding principle of hydroponics, using water rather than soil to grow plants, hasn’t changed. No matter the system used, it all depends on water and the movement thereof.

Contemporary hydroponics does offer a lot of upgrades compared to the systems used over the past thousand years, though. And it’s not just technique and equipment upgrades either. Now we have advanced techniques for monitoring water and nutrient levels, intricate calculations for plant and tower spacing, man-made growth mediums, and so much more.

We now have the capacity to create huge, eco friendly and energy efficient greenhouses so massive that they’re referred to as ‘plant factories.’ Likewise, we can create home hydroponic systems that can grow anything from strawberries to miniature fruit trees.

Because of our technological advancements, we’ve been able to further increase the efficiency of hydroponic systems and create new techniques like aeroponics and fogponics.  Innovators across the globe are sharing knowledge and contributing to the growth of hydroponics as a field of its own.

A brief look toward the future of hydroponics

In the history of hydroponics we find millennia of innovations and developments. Though slow going at first, hydroponics has literally revolutionized cultures throughout history and brought prosperity as a result.

It’s worth noting the exponential development of hydroponics within the past century especially. As with any other technological development, we’re in an age of rapid growth. Hydroponics systems can be expected to accompany any space colonization, as we’ve seen through aerospace research.

We’ll surely see an influx of newer, more accessible hydroponic methods. Because of hydroponics’ high efficiency and environmental benefits, it’s already being looked at to solve issues with traditional soil agriculture. It’s not a far leap to expect to see hydroponic overtaking field farming, especially considering the ‘plant factories’ we already see popping up across the globe.

No matter what, we can look at the history of hydroponics and see that it’s been a staple of human innovation. That will always continue, as will the drive of human nature to improve, innovate, and find new ways to bring prosperity to our societies.

How To Germinate Seeds For Hydroponics: Step-By-Step

How to germinate seeds

One of the most crucial steps in a hydroponic garden that is often overlooked is getting the plants in the first place. There is lots of talk on pH levels and nutrients, but these are only suitable for existing gardens.

An up and running system is very different from a germination area, and with the speed that some plants will be growing, you will need to be continually germinating your seeds to keep your garden stocked with new plants to grow.

There are lots of people who skip this step and purchase seedlings that they can drop right into their system. Although this is more convenient, it does mean you might be limited to what you can grow.

When growing from seeds, your plants will bypass any trauma, damage or passing on disease like they would as if they were raised in soil, or other mediums and then transplanted from an outdoor environment into your system.

One other aspect many growers forget is, they can get many more seeds for the price it costs for seedlings.

Although germination of seeds and seedlings can be pretty straightforward, and nature will do some of the hard work for you, there are some bits of equipment you need, terms you need to know, and some specific steps you need to follow to get the best germination rates.

When first starting to germinate from your own seeds, it will be a little more expensive because of the equipment you need to purchase, however, once you are on your way, this cost will be easily absorbed by the number of plants you can grow from seeds.

Hydroponic Germination Basics

One thing to note right at the start is, seeds can be germinated in soil, but it is advised against doing so. This is for a couple of reasons.

Bacteria can be passed over from the soil to your hydroponic system, and second, it can damage your seedlings roots because they will need washing before they are transplanted. It is far better to use a dedicated growing medium for this such as Rockwool or Coco coir/ Coco peat.

One other thing which is worth mentioning is, there are a lot of places that classify seeds as Hydroponic Seeds, there is no reason to search for this because any seeds are suitable for use in a hydroponic system.

Steps of Seed Germination

When seeds begin to germinate, they start in a dormant state, and then as they grow, they reach an active growing state.

There are 5 parts in this phase and can be seen here:

  • Seed coat – this is the hard outer shell of the seed
  • Plumule – these are the first shoots or stems of an embryo plant
  • Hypocotyl – this is the part beneath the stalks of the seed leaves which sits directly above the root system
  • Radicle – this develops into the first root
  • Cotyledon – these are the embryonic leaves which develop in seed-bearing plants. There will be one or more of these first leaves that you will see from germinating seeds. These help retain nutrients until more dominant leaves start to grow.

When the dormant state comes to an end, the Radicle will crack, and from this, there will be an early shoot. For this to happen, the seeds need to be in warm moist conditions. It is the function of the Cotyledon to provide the seeds with its first nutrients, this they would traditionally get from the soil, but in hydroponic systems, there is no chance for them to do this.

Propagation is the name given to the phase where seedlings start to become stronger, and when they develop stronger roots and their first real leaves. This phase of growth begins as plants emerge from the seed, and ends as they develop roots that have taken hold inside the germination plug.

When plants have developed two or three sets of real leaves, this is the stage when they can be transplanted into the system.

Equipment Needed For Hydroponic Seed Germination

Although there are a few types of growing medium you can use for germinating seeds, it is worth running through them so you can see how they work in your hydroponic garden.

Coco Peat

This growing medium is a byproduct of the coco growing industry. It comes from the coir fibers and is washed and heat treated before it is made into coco peat products. Most often you find this in the form of large bricks.

The properties that are unique with this medium are, it is sterile, and has natural rooting hormones. It also possesses antifungal properties while being 100% organic. Coco peat can be used anywhere where you would previously use peat moss. Other properties are that it is capable of holding 8-9 times its own weight in water.

Coco peat can store and release nutrients for extended periods to plants, and it delivers fantastic oxygenation properties. Natural pH levels of coco peat are 5.0 – 6.8, so it is bordering neutral and slightly acidic. The one downside of using Coco Peat is some of the loose particles can be washed around your system. This can lead to pump blockages and reservoir sludge.

Coco Coir

This growing medium comes from the same processes as coco peat, but it isn’t ground into fine powder. It differs because it is the hairs that are found on coconut husks. It is most often used in passive hydroponic systems, but it can also come in the form of starter cubes or larger cubes for use later in your system.

Coco coir comes with all of the same properties as coco peat and is an excellent growing medium all around, but it can suffer from the same downside. Coco coir is not clean, and sediment can be washed off leading to the same pump clogs and reservoir sludge buildup. It can be rinsed before use to remove any of these loose particles.

Rockwool

This growing medium isn’t natural and is made by the heating and spinning of specific silica-based materials into thin threads. This is the same process that roof insulation is made with, and should be treated with the same precautions during use.

Rockwool delivers an ideal material which when used, has an almost perfect oxygen to water ratio while being pH neutral. Most often it comes in the form of cubes or plugs at around 1-inch square that are ideal for starting your seeds.

Once these are on their way with germinating, they are easily transplanted into larger cubes that have a hole precut to accommodate the plug. The smaller plugs are also ideal for transplanting into other growing mediums and are suitable for NFT, drip, and deep water culture systems.

Rockwool grow cubes have a pH of around 7.8 which is a little on the alkaline side.

These three mediums can be interchangeable, but for the remainder of this article, we will use Rockwool as the point of reference.

It needs noting, that because Rockwool is like insulation materials, it can make you itch, or breathing the fibers can be harmful. You only need to handle this material as much as required without any unnecessary touching. 

Other items needed

  • Containers that are capable of holding water, Germination tray with dome
  • Chemicals for raising or lowering pH levels
  • Seeds of choice
  • Grow lights if germinating indoors
  • Heating pad if temperatures are lower than required

Germinating Seeds Using Rockwool

Step 1: Hydrating and Stabilizing

Depending on the number of seeds you are looking to germinate, you might need one or more containers. These need to be big enough to hold your Rockwool cubes once they have been soaked in water.

If water levels are too high, the seeds can drown because of the excess water. The seed needs to be at a height where the water can wick up the cube to the seed, but also, there is air available for the seed from above.

At this early stage, you can use distilled water or regular faucet water. Both will work equally as well as each other. Once you have the water in your container, you need to test the pH levels. There are a few growers who recommend adding a half strength or lower nutrient solution, but at this stage, it isn’t necessary, and the seeds won’t benefit that much, and in some cases, once nutrients are added to sprouting seeds, they have died.

Using either a pH test kit or a pH testing meter take a reading. Depending on the type of water you use, it might read up or down, but you might find the water gives a reading of 7.4. This means you will need to lower the pH by using your pH down solution.

The pH you need to aim for is as close to 5.5 – 6 as you can get. At no point should you let the pH drop to below 5.5. The fibers of the Rockwool can become damaged when this happens.

Insert your starter cubes and let them soak for around an hour. By this time, they will have swollen by soaking up the water from the container.

Rockwool cubes have the ability to hold the perfect balance of air to water ratio. If there is unnecessary squeezing, this will change this ratio and can cause deformation of the cube. The cubes are capable of remaining wet for a few days without any additional watering.

If you are presoaking your cubes in pH balanced water before moving them to another tray. Don’t discard the water, and keep it in a sealed bucket for later.

Step 2: Planting Seeds into the Cubes

Depending on the supplier of your Rockwool cubes, you might have the ones which come without holes already in the cubes. If this is the case, all you need to do is make a hole in the top which is to a depth of no more than a quarter of an inch deep.

Now, all you have to do is take a couple of seeds and carefully place them into the hole. They won’t fall to the bottom so you will need a small device to gently push them to the bottom of the hole. Once done, you can gently push another little piece of Rockwool into the hole to cover the seeds. Make sure this is only tight enough to block light from entering.

It might seem backward, but what you do now is cover the container. This will leave the seeds in darkness, but it will also retain moisture and prevent evaporation. It is this environment which is critical for seeds to germinate correctly.

You can purchase dedicated germination trays that come with plastic domes, this isn’t necessary. Other growers also slide their trays inside a Ziploc bag to retain moisture, this though does mean your trays will be much smaller. All you need is an upturned tray of the same size or something that can sit across the tray without pushing on the Rockwool cubes.

No matter what you use to cover your tray, be it a Ziploc, or a plastic dome, your trays need to sit in darkness throughout the germination period. The area where you have your seed trays laying should be around 68F, if your growing/ nursery area is less than this, then this is where the heating pad comes into use. A few degrees above will be fine, but it is below which really causes the problems.

Step 3: Let Nature Take its Course

While the seeds are germinating in this phase, you do need to check water levels on a daily basis depending on how warm your environment. This is one of the advantages of using Rockwool because you might find they don’t require any, or minimal watering during this time.

This is where you can use the reserved water from the first step, simply add enough to keep the blocks moist as water levels drop.

This is also why it is advisable not to add any nutrients at this stage. Sprouts are becoming stronger, and only really need nutrients once they are in your system.

As you added more than one seed to each hole (there will be mortality rates or slow growers), you might find that both have sprouted. It will be tempting to try and remove the one and replant, but you should avoid doing this. It can cause damage to the other sprouts rooting system.

This stage is usually reached in around 3 – 4 days depending on the growing conditions. When you see the first true leaves emerging, it is time to select the smaller of the two shoots and cut off the more minor one’s level with the top of the cube. It is a sacrifice you need to make, unfortunately.

Once plants have reached this stage, it is time for them to start receiving light to help them grow. Many people use sun-facing windows to deliver this light, and although ideal for the first introduction to light, it can cause problems later.

If you use the sun or grow lights, it is the red-light frequency that will accelerate seedlings growth. When using the sun, three hours per day is enough, and the times that contain most of the red light is between 6.00 am, and 9.00 am or later in the early evening from around 4.00pm until 6.00 pm.

Using the window method will require the trays to be turned so the seedlings won’t lean toward the light. Additionally, once your seedlings are getting bigger, they will need up to 15 hours of light per day.

This is where a sun-facing window leads to problems, there might not be enough sun. When this happens, and seedlings don’t receive enough light, they grow weakly and leggy. Once this happens, they begin falling over, and in many cases, it is something they are unable to recover from.

Overhead grow lights solve this problem because you can set the timer for 15 hours per day, and because the lights are overhead, the seedlings won’t lean to the side. Additionally, as they are receiving a full quota of light, they will grow much stronger and healthier.

One other thing to note is that seedlings need time to rest from light, so when they have had their quota, the nursery area should have sufficient darkness.

One final caution is to make sure any grow lights are positioned far enough away from the top of the seedlings so as to not scorch them (depending on light type). As they grow, the lights will need raising. Watering might become more frequent as the seedlings begin taking on more fluids, and if there is heat from your lighting fixtures.

Step 4: Transplanting

The first steps of germination to when you can transplant into your system can take between 2-3 weeks.

Rather than waiting for this time limit, you can check the bottoms of your Rockwool cubes, and when you see the roots are starting to protrude from the bottom, then you can transplant. This can be a good indication because if you leave them too long, they can begin to get root bound in the cube as this will be their only source of moisture.

Once you have reached this stage, you can clear a space in your system for your new young plants. You can transfer the whole plant along with the Rockwool cube into your growing media where you should cover the top lightly.

Because the plants rooting system has been focused on the cube for moisture, it needs a chance to naturally seek out another water source, so, to enable them to do this, you can top water them for the first few days.

Why Haven’t all My Seedlings Survived?

There are numerous reasons why not all seedlings will survive, and not all can be explained. But, depending on plants being grown, there are temperature differences that must be accounted for. if you have cool weather plants, and warm weather plants as seedlings in the same environment, then this could be too much of a temperature swing for either type of plant.

Other things you need to be wary of are as follows:

  • Media drying out – seeds need to be in a warm moist environment to germinate. If they dry in between watering, this can kill them or prevent them from sprouting.
  • Retain high humidity – this is essential to retain moisture. Humidity domes or an upturned tray on top of your grow tray can help maintain moisture and humidity. A transparent dome while under lights will also be beneficial.
  • Too wet – if you over water, or your Rockwool cubes become too wet, this can lead to seeds rotting before they have a chance to germinate properly. To make sure you don’t over water, you can spray inside your grow tray rather than pouring water. Many grow trays have ridged bottoms so the grow cubes won’t be standing in pooled water. If a too wet situation happens, you can have what is called damping off. Here, some molds and fungi form during the propagation phase and cause your seedlings to lose the structure of their stems and lay flat.
  • Don’t overfeed – when you start feeding with nutrients, this should only be when you see the first sets of true leaves. The EC of your water should be at a maximum of 0.8 – 1.2. During the early stages of life, plants will obtain all their nutrients from the cotyledons, and it is only when these first true leaves show they become dependent on external sources of nutrients or fertilizers.

Transplanting Tips

This might appear a simple exercise, but at this stage, plants will be susceptible to transplant shock. This isn’t only from the pressures of being removed from the grow tray, but also from being placed into a new environment. This initial shock can take them a few hours to recover from.

Seedlings are heat sensitive, and even more so when being transplanted. This will include their new life under stronger lighting, but also the temperature of your nutrient mix.

The ideal time to transplant is when your seedlings are ready to be watered. The grow cubes will be slightly moist and will have shrunk back a little in your grow tray. This will make them easier to remove, and when they should be placed into a system that has running water.

Seed Tips

Although there are lots of seeds that are suitable for germination, some more exotic plant seeds do have special requirements. Here is a brief overview of what you might find when looking for seeds.

Pre-soak seeds – some growers advise to presoak seeds before germination. This would allow the seed coat to become saturated and break open easier. However, because hydroponic germination methods are in the mid 90%’s compared to soil, this is not recommended unless the speeds specifically require soaking.

Scarification – many fruit plant seeds might require their exterior to be weakened before germination. In nature, this is the function of animals or birds. To mimic this in hydroponics, this type of seed will require some form of scarification. This might include the seeds being run along a metal file, rubbed across sandpaper, cracked lightly with a hammer or even cut with a knife. If you have any seeds of this nature, be sure to only carry out this process on the seeds you will be using. Once they have been scarified, they will not store very well.

Seed inhibitors – because some seeds expect to lay dormant over the winter period, they have built-in inhibitors that prevent them from germinating too soon. Some of the inhibitors can be found in the way of Abscisic acid. This would decrease in the seeds as winter comes to an end, so the seeds are ready to sprout. To overcome this, you can place this type of seed in a moist growing medium and placed in a refrigerator for four weeks. This process is called stratification, and it is by doing this that enzymes break down and mimic what happens in the wild. Temperate native plants that require this winter season will need this process. It might be uncommon, but it is useful knowing how you can work around it.

One other inhibitor which can be found in desert plants is phenolic compounds. This prevents the seeds from germinating until there is sufficient moisture, This inhibitor is water soluble, and once it has been broken down, then the seed is able to sprout. All it requires for these to sprout is sufficient moisture.

Temperature – We have spoken about temperature, but it is worth mentioning the upper heat limits because this can prevent seeds from germinating, or even killing them. If the growing media rises above 90F, then you will unlikely see any action. You can check this with a hydroponic thermometer quite easily. In many cases, this happens in greenhouses where growers germinate, but having the ideal temperature is crucial.

Conclusion

There can seem to be a lot of information to take in when it comes to hydroponic seed germination, but in practice, it is quite straightforward when you follow the requirements. The amount of equipment is minimal, and the only things are to make sure you have an area that you can use as a nursery.

In many cases, it can be something as simple as a shelf racking system where you can store your trays and is away from your system grow lights. If you use this, you can easily keep your seeds covered until they are ready to be introduced to grow lights, and the amount of shock they will face during transplanting can be reduced.

With the length of time required before transplanting, you can have seedlings at various stages and always have a continual supply of plants that you can add to your system. This makes the system more efficient overall.

Growers also find that growing their own plants from seeds, is not only cost effective, but it is also gratifying to complete every single stage of their plant’s growth.

How hydroponics Can Solve World Hunger

Our current global situation is quickly emphasizing the vast issues of food shortages around the world, especially in impoverished areas. We’re more connected than ever due to technology, and with the influx of media and social groups focusing on the issues surrounding these areas, scientists and philosophers alike are looking for new solutions. Currently, at least 1 in 7 people aren’t getting the sustenance they need. This food shortage is only expected to increase as the global population continues to grow exponentially. Everywhere, we’re looking for solutions; from our own backyards to labs overseas, the crisis is demanding attention.

The dream of solving world hunger is by no means a new one. The difference is that now we have practical methods of implementing a solution. A developing solution that’s been proposed is the use of hydroponic systems. Hydroponic gardening offers increased crop yields, while using less of the traditional resources used in soil grown crops.

What factors contribute to the hunger crisis?

There are a lot of reasons that the global hunger crisis continues to grow. Remember, hunger is affecting people everywhere. Not just the arid countries you’ve never visited, not just the community you saw on the news; hunger exists everywhere and it comes in many forms. From impoverished countries where citizens may go hungry for days to cities in developed countries where school children don’t have access to fresh produce, to rural areas where food is scarce, all these forms of hunger are prevalent. It would be a monumental undertaking to list every single factor that contributes to global hunger. However, to really grasp the problem and thereby understand the facets of hydroponics that create a solution, we need to look at some of the most basic, common factors of global hunger:

Climate and environmental factors

Climate change is a huge factor contributing to food shortages, and it isn’t expected to let up. Flooding, irregular weather patterns, drought, the changing of conditions during traditional growing seasons, they all make growing food harder. Where weather patterns and average temperatures used to be predictable and reliable, farming could be put on a regular schedule, and crop yields were more or less predictable. That’s no longer as stable and as a result, crop yields are in flux globally.

Poverty

Poverty shouldn’t affect whether or not people can get reliable sources of food, but it sadly almost always does. Everyone has heard (or very likely uttered) the phrase, “but healthy food is SO much more expensive.” And that’s a pretty fair statement. For the price of a spaghetti squash weighing about 2.5 lbs, just about any fast food meal can be had instead and for even less money. Unfortunately, the human body wasn’t meant to exist by depending on empty calories. Even in areas where food is accessible, it still might not meet nutritional needs. In impoverished areas, there isn’t even this less nutritious but still edible alternative.

Transport and Access

Access to food isn’t always as easy as going to the grocery store or food pantry. Sometimes people suffer from food insecurity as a result of their own lack of transportation to food sources. That’s a problem that can be mitigated by an in home hydroponic system. However, we need to recognize the source of the majority of our crops as well. About 70% of our crops are grown in remote or rural locations. That means they require transportation to reach most people. Which in turn means a heavy reliance on fossil fuels, creating more expense involved in food transport. 

Why should we stop looking for answers in traditional soil farming?

To be fair, traditional farming is an important staple to many people worldwide, and they rely on it to produce the crops they buy in the supermarket or eat in restaurants. Likewise soil farmers rely on soil grown crops to provide their livelihood. But in terms of helping to provide a solution to the global hunger pandemic? Maybe not so much. So, let’s briefly look at the reasons soil farming isn’t the ideal, or most efficient solution:

First, a lot of impoverished areas don’t have the resources to support much traditional farming, nor the economy to support farming that would grow enough crops to provide sustenance. When it’s used in desperate regions, there’s often an issue of unregulated pesticides and chemicals, which then run off into natural water supplies. That means main sources of water are no longer safe to drink. Not only that, most farming uses sprinkler irrigation which actually lose about 60% of the water used. In countries where water is as inaccessible, or more so than food, that presents a pretty big problem.

Then, you have the issue of cost. Traditional farming costs far outweigh those of hydroponic farming, and it produces less crop yield versus that of a hydroponic system. The last big point to make is that farming is seasonal. At least in the vast majority of cases. That takes a big chunk out of the usability of the land for food production, and essentially leaves land unused despite the scarcity of arable land.

What makes hydroponics an ideal solution?

Hydroponics has been the hot word in a lot of conversations lately, but it seems like the discussions are taking place primarily in more affluent, developed regions. We know it excels as a method of gardening (at least in our homes and hobbies) but what makes hydroponics such a good solution for ending world hunger?

It answers the problem of land shortages

In many areas, arable land isn’t available or if it is, it’s very sparse. That means a lot of people don’t have the means to produce their own food, much less the money to purchase it. Hydroponic systems don’t require acres of land to produce significant crop yields. They require very little space for the amount of crops that can be produced in a single system. Because of this, individual or shared systems can produce food in any community.

It answers the problem of limited resources in growing crops

Traditional farming and gardening isn’t always readily accessible and oftentimes that is, in part, due to a lack of resources. The traditional methods require much to produce a successful crop. That means a lot of water, land, fertilizer, pesticides, and labor. Hydroponics uses significantly less of these, and none of some of them (pesticides are rarely if ever used). In fact, hydroponic systems can use up to 90% less water than soil farming. This knocks down several barriers for individuals faced with hunger and a lack of resources.

It can be used worldwide, regardless of climate or situation

One of the great things about hydroponics is that it can be used just about anywhere. Regardless of climate, hydroponic systems can be used in conjunction with greenhouses and heaters to ensure crop growth. Likewise, whether located in a rural or urban environment hydroponic systems thrive.

Materials for systems can easily be acquired

While there is a cost associated with any system start up, many of the components needed for a hydroponic system can be found or acquired easily. That means that items like an old fish tank (so long as it doesn’t leak), spare gardening pots, barrels, old trays, and so much more can go into the creation of a hydroponic system, without the need to have money to purchase many components.

Can a hydroponic system provide enough nutritional content?

This is a common question, especially in more westernized countries. Oftentimes we greatly overestimate the amount of protein required in our diets. Likewise, we also tend to greatly underestimate the protein that can be provided in a vegetable and fruit based diet. People need about 10-35% of their daily caloric intake to come from protein, which means about 50 grams daily (depending on age and weight). A hydroponic system is capable of providing significantly more than that. For example, the protein content of one cup of green peas is 9 grams. A hydroponic garden with about 30 plants per person (assuming this was the only protein source) can yield up to 6 lbs per harvest. With the ability to grow up to 5 harvests yearly, there’s enough protein to support the needs of most individuals.

Note: this is just an example to show how even the daily nutrition we think can’t come from produce, in fact can and does. It’s still important to diversify our nutrition sources.

What about our other nutritional requirements?

That’s pretty much a non issue. Since hydroponic systems can be used to grow just about any plant, that means we can use them to provide all our daily requirements. Nutrients like calcium, potassium, and vitamins can be found in many fruits and vegetables, and in more than sufficient quantities. The best way to ensure all our daily nutritional needs are met is through diversity. By setting up a hydroponic garden with various plants, a single system has the potential to provide all the nutrients people need. Alternatively, individuals can grow specific crops and trade or barter with neighbors to help meet each other’s needs.

Where can hydroponics be used?

Anywhere. Yes, hydroponics can be used to grow plants just about anywhere, so long as considerations such as temperature, light, and ventilation are also modified to fit the climate. The plus side to adding in considerations to mitigate otherwise harsh environments is that hydroponic systems still remain accessible, and pretty easily modified to the grower’s needs.

Nasa began hydroponic research and development to provide a way to grow plants in space. So, if we can achieve a healthy hydroponic harvest in space, it’s more than safe to say we can do it anywhere on earth. That means from the Arctic circle to desert climates, to areas that poverty stricken and lack verdant land. Hydroponic systems can be put into huge warehouse sized greenhouses, or tiny unused spaces in already cramped apartments. So, when you hear ‘hydroponic crops can be grown anywhere,’ believe it.

How does it help?

It provides food that people need. Obviously, that’s far too simple an answer when you look at all the benefits hydroponic growing provides to individuals and communities. The neat thing about it is that hydroponics really can help people in large variety of ways, and those ways change depending on their needs.

For impoverished areas where food is scarce, it’s a much more affordable, more sustainable option. Not only that, it can be done by the individuals in need rather than requiring money to purchase sustenance. Plus, it provides a valid source of income to many families in these areas. It’s been shown that a single hydroponic garden can provide upwards of $90 to around $250 every couple of months in impoverished areas in places like South America and Asia. Maybe that doesn’t sound like a lot to those of us that live in first world countries, but for the vast number of people that have to survive on less than $1 daily (and would be lucky to earn as much), that’s literally a life changing garden. That’s a livelihood.

Hydroponics even benefits those who are not food insecure like in developing countries, but that struggle to get enough nutrition even in the first world. Low income families can take advantage of hydroponic gardening as a means to supplement their diet with wholesome food that they may otherwise struggle to obtain. Even food secure individuals can use a hydroponic garden to eat healthier and put a dent in their grocery bill.

In many developing countries, there’s less regulation regarding the use of chemicals and pesticides in crops for consumption. This puts vulnerable populations at even more risk, as there often aren’t alternative food sources. Hydroponic gardens don’t require the chemical elements of traditional farming, nor do they produce harmful runoff or cause undrinkable water and harmful algae blooms. So, it helps us maintain our environmental health too.

What resources are needed?

A lot of the uninitiated picture hydroponic gardens as the commercial scale greenhouses that appear so frequently in images. The truth is, any hydroponic method of growing is scalable, and therefore doesn’t require a huge greenhouse setup. The essential elements to construct a hydroponic system consist of:

  • A tank or water reservoir
  • Growing medium
  • Trays or towers to secure plants
  • Nutrients (aka plant food or hydroponic fertilizers)
  • Supplemental lighting
  • A water pump (for many types of systems, but it is not required for all)
  • Ventilation
  • Heating (in some systems this may or may not be required)
  • Water
  • Suitable seeds, seedlings, or transplantable plants

Some of these essential components are easier to come by than others. As noted before, even old fish tanks or large ceramic pots can be used in lieu of a traditional reservoir. As far as water pumps go, wick systems don’t require one, so when push comes to shove, hydroponic systems can be constructed to work without a pump if the cost is an issue. In cold climates, heating will be required, but as we’ve seen through Iceland’s example (by using geothermal vents to heat greenhouses year round), it can certainly be done.

Growing mediums come in so many forms that it’s almost difficult to think of a scenario in which they aren’t accessible. Whether perlite, rice husks, or stone wool, there are several options that fit any type hydroponic grower.

Trays are easily constructed from readily available materials for growing plants horizontally, as are materials to construct towers to grow plants vertically.

Many of the resources that require electricity (such as pumps, lighting, heat, ventilation) can be made not only more efficient, but more accessible with the use of batteries, generators, and/or solar power.

Seeds and plants will be easily found in some areas, and may be difficult to obtain in others. Where seeds are difficult to come by, they can be obtained either through ordering, bartering, or with the aid of humanitarian organizations.

While there is an issue of water shortages, it is more easily overcome than you might expect. Some solutions include gathering rain water, treating existing water sources, and using a recycle system for hydroponics. Compared to the water requirements for farming, the water demands of hydroponics are minimal.

Obtaining nutrients can be done in several ways. Nutrient solution can be bought in wholesale bulk, and created through homemade methods (so long as the nutrient ratios and EC testing are done properly).

Is there data that support the use of hydroponics in food insecure areas?

While simplified hydroponic projects have been implemented in some food insecure areas since as early as the 1980s in Latin American and African countries, there are enough studies and projects from then to the present that do show hydroponics can be put to good use in these nutrition deficient places. In short, not only is there data that support hydroponic use in these areas, but there are also successfully implemented projects that demonstrate the utility of hydroponics.

Another case of a successfully planned large scale hydroponic implementation was staged in tropical Asia by Bradley and Marulanda. They found that by establishing 50 million hydroponics gardens, they could support the nutritional needs of the 232 million individuals suffering from food insecurity. That’s factoring an average family size of 4, with some room for variation. These gardens would cost about $355 not just for initial set up, but for an entire year’s supplies to keep it running including nutrient solution as well as seeds.

While this may seem like a large investment when taking poverty issues into account, looking at the revenue figures provides a clearer perspective:

Total project cost: $20 billion

Single garden setup and 1st year costs: $355

Total project yearly revenue: $135 billion

Single garden yearly revenue: up to $1405

Variations of hydroponic gardening provide even further reach

If you’re unfamiliar with aeroponics, it’s a newer type of hydroponic system, also used by NASA in research for growing plants in outer space. As more minds contribute to the solution of solving world hunger, we see more innovation. Part of using hydroponics to fix hunger is getting innovators and contributors to expand solutions.

One such case comes from a recent product design grad that took aeroponics to an accessible level. Nikian Aghababaiecreated a low cost aeroponic kit that uses entirely locally sourced and recycled materials and has hardly any maintenance costs. Using locally sourced seaweed a nutrient solution is created (and yes, it’s totally adequate for growing and has proper EC levels), so even the cost of nutrient solution is taken out of the equation.

While this isn’t as widespread as the traditional hydroponic systems we’ve been talking about, it just reminds us how important it is to continue innovating and watching for solutions that leverage hydroponic technology to make food go farther.

So what’s our main takeaway here?

Hydroponics provide a formidable solution for solving hunger, but it also provides us ample room to continue building, improving, and extending accessibility. And we’ll need that to conquer a huge issue like world hunger.

How can using hydroponics as a solution to global hunger be accomplished?

Look, global hunger is no small issue. It can’t be tackled overnight, and it’s going to take a lot of work and cooperation to make a solution work. The beauty of using hydroponic systems to alleviate the hunger pandemic is that it can start small and grow into a much larger solution. Hydroponics can be started in a single home and grow into a community wide project.

While the idea is great, we still have to consider what it will physically, financially, and logistically take to implement hydroponic systems to absolve our world of hunger. Hydroponic systems don’t need to expensive or fancy, but at the end of the day you still need materials to make one. Some components like a tank and growing tray are more easily acquired without cost. Items such as water pumps and testing kits will have to be purchased or donated. In addition, water will have to go through a purification process in many regions to make it usable. Supplies to create solar powered systems, generators, and batteries will often need to be provided as well.

How can we get these supplies to food insecure areas?

That’s one of the hardest parts of implementing a solution to world hunger. In truth, it will take a lot of cooperation from international aid organizations, governments, and grassroots organizations. Global organizations like The World Bank and United Nations Food and Agriculture Organization are already exploring and implementing hydroponic garden installations in food insecure regions.

What scale are we looking at?

The global eradication of hunger is a project of massive scale, and the need for food is only expected to grow. By 2050 this need is predicted to rise at least 60%. There’s a lot of planning to be done to determine the exact scale of the systems that need to be implemented, but we can come up with some ballpark numbers in the meantime:

Let’s say 800 million people are currently food insecure (according to the latest UN statistic). Keep in mind that realistically the level of need in this group will vary anywhere from lacking fresh produce, to literally being on the verge of starvation. For our purposes however, we’ll use this as a static figure.

Using the above studies as a baseline, we can simplify the problem to make the numbers easier to get our heads around. Assuming an average family size of 4 again, we can say that one garden supports one family.

To produce enough food for the currently 800 million food insecure people, we will ultimately need about 173 million working hydroponic farms and gardens.

What kind of funding is needed to make this happen?

Donated supplies can be obtained to significantly reduce the cost of building these systems, and there are plenty of innovators creating low cost kits to help implement hydroponic systems. To create a hydroponic system that’s able to support an average family, we’ll use the above figure of $355. That means to create sufficient hydroponics systems approximately $6.14 billion in funding would be needed. These costs can be subsidized by using recycled and donated materials, as well as using low cost start up kits where appropriate.

It’s unreasonable to expect any single entity to provide all the funding to implement this solution. Realistically, several different organizations will need to coordinate to provide not only funding and supplies, but education and assistance.

Thinking small on a big scale

The truth of the matter is, hydroponics works better as a solution when we stop looking at it like traditional farming methods. That restrains our ability to create solutions with these systems. We can’t hope to make this happen overnight but through consistent effort and development, it can become a sustainable solution. There have been so many valuable studies that show hydroponic gardens provide more than food, they can provide a livelihood that supports families and sustains the growth of the garden.

How to Test EC in Water – Complete Guide to Electrical Conductivity

Testing EC of water

Hydroponic growers are faced with many challenges when it comes to monitoring their nutrient solutions and pH levels. We know this can affect how plants grow because some plants require very different ratios to grow to their full potential.

If these two factors were challenging enough, there is one more element in nutrient solutions that needs constant monitoring and adjusting when required. This is the EC level, and here we will see how it affects your plants, how you can test it and how you can adjust it if needed.

Understanding EC Levels

What is the EC in a Nutrient Mix?

EC is the measure of electrical conductivity in any solution. You might also see it as CF which stands for the ‘Conductivity Factor.’

On many occasions, you will see this EC written in conjunction with nutrient solutions pH levels. At this point, you need to know the difference between the two.

The pH levels of your nutrient mix give an indication of nutrient balance in your mix. EC, on the other hand, is an excellent guide to the quantity of available nutrients in your solution.

To make this easy to understand, distilled water contains no EC because it has no minerals contained in it. Once there is an introduction of minerals, salts are dissolved, and then the solution can conduct electricity. The higher the amount of salts, the higher the EC level or the electrical conductivity.

One thing worth noting with EC levels is, it doesn’t tell you what nutrients, and at what levels they are at, it is an overall number of nutrient concentration.

EC Levels in Hydroponics and Why They are Important

Just like pH levels in your hydroponic system, and some plants prefer different levels. It is the same with EC levels, and various plants prefer different levels. On top of this, most plants like the EC level to be in the range of 1.2 – 1.6 in their vegetative stage, and once they reach flowering, they like the EC to be in the range of 1.6 to 2.4.

These levels are worth knowing because, from the following three plants, you can see a vast difference between what levels they prefer.

  • Basil & other herbs – EC 0.8 – 1.4
  • Tomatoes – EC 2.2 – 2.8
  • Spinach – EC up to 3.5

Now we know what can affect EC levels, we need to understand why they are essential. These levels provide a detailed indication of what is happening in your nutrient solution, especially when tests are carried out as an addition to testing pH levels alone.

Here is a brief overview of what is happening with plants when the EC levels change:

  • EC level remains the same – the plants are absorbing the same amount of water as nutrients. When this happens, and reservoir levels drop, you need to top up with a nutrient mix of the same strength. This does still require checking once it has stabilized and run through your system.
  • EC levels drop – when this happens, it shows the plants are using more nutrients (salts) than they are using water. When this happens, you need to top back up your reservoir to the level it was, and it might mean you need to make the concentration of your newly added nutrients a little stronger. This does need to be checked after topping up in case your solution ends up too strong.
  • EC levels rise – this happens when your plants are using more water than they are using nutrients. You may have seen this and know the symptoms as ‘Nutrient burn.’ To resolve this, you need to dilute the solution with more water. Again, your solution will require checking in case it falls off and goes in the opposite direction.

EC Levels and Plant Growth

There are a few things growers should know about EC levels, and this is what happens to a plants growth, and what factors can make EC levels change. There are elements which can affect these levels aside from the amount of nutrients plants are absorbing.

We have seen why these levels are significant, and here is how it affects plants during different stages of their growth.

How Conductivity Levels Will Affect Plant Growth

Seedlings, cuttings or delicate plants will suffer from nutrient burn when the EC level is too high. This ‘too high’ doesn’t mean you have it wrong because even a nutrient mix that is suitable for larger plants can be too strong. To make sure your plants don’t suffer from nutrient burn during these stages, it is advisable to run your nutrient levels at half strength or lower.

Once plants become more substantial and are entering their vegetative stage, you can increase the nutrient concentration. This is still dependent on the type of plant you are growing. If you have a mixture of plants, you need to separate these into light feeders, medium feeders, and heavy feeders if possible. If you have three different types of plants which all feed at different rates, this means you will need three separate reservoirs.

This might seem too much, and it might not fit in with everyone’s hydroponic system, but as a good example. If you feed lettuce with high EC levels that are suited to tomatoes, then your lettuce will become bitter. At the other end of the scale, if you feed tomatoes with low EC levels intended for lettuce, then your tomatoes won’t have any taste.

Can Water Temperature Affect EC Levels?

Nutrient solutions in your reservoir should fall inside the temperature range of 65 – 80 degrees Fahrenheit. Plants don’t like a rapid change in water temperature. This is more important around the root zone. When you are about to add water to your reservoir, you should make sure it is at the same temperature as what is already in the reservoir.

If your grow room is indoors and you fill from an outside hose, this could cause too much of a difference.

Ambient temperatures will also have an effect, so depending on where your system is situated, you might need to make use of an aquarium heater for colder regions, or a suitable chiller for your nutrient solution if you live in warmer climates.

How Does Air Affect EC Levels?

All growers know that plants require airflow to grow correctly, but many are not aware that ventilation plays a significant part in EC levels.

One thing to note is that airflow isn’t the same as ventilation. Airflow is the moving of the same air while ventilation is discarding of old air while introducing fresh air. When you have improved ventilation in your growing area, this aids much higher rates of transpiration. From this, plants will increase their rate of nutrient absorption and uptake.

EC Management

When you have a good EC management procedure in place, you are in a position to help your plants deal with changing conditions. Many growers use low-light conditions and raise their EC levels. This restricts vegetative growth and helps counteract stretching.

When plants are in low humidity areas with high heat, growers can reduce their EC levels to ease any stress on their plants.

Testing EC Levels in Hydroponics

Testing EC levels is no harder than testing pH levels in your solution, but there are a few terms and things you should know.

Terminology Related to EC Levels

  • EC Electrical Conductivity. A measure of the total dissolved salts/ solids in your nutrient solution.
  • CF – Conductivity Factor. Another term for the above EC.
  • TDS – Total Dissolved Solids. This is read in ppm (Parts Per Million)
  • PPM – Parts Per Million. This is a standard measuring unit of elements which are in your nutrient solution. When you have one ppm, this equates to one part of the (solid) weight of any given mineral in one million parts of the solution.
  • MilliSiemens – this is a measure of electrical conductance

Converting Between TDS and EC Values

Again, this might sound complicated, and when you come to take readings, your testing meter will do this conversion for you for whichever value you are using.

When you want to find the approximate values of sodium chloride (salt) TDS in your solution, all you need to do is to multiply your EC reading (in milliSiemens/cm) by 1000, and then divide the result by 2.

If you want to convert the other way to find out an EC level from a TDS reading, it is a matter of doing things in reverse. All you need to do here is multiply your ppm reading by two, and then divide the result by 1000.

It is far better to rely on a meter when it comes to taking readings than converting manually.

The EC vs. TDS Debate

There has been a debate in the hydroponics world, and this is because you can test nutrient solutions with different TDS meters and come up with mixed results. This purely boils down to there being different conversion factors, and some manufacturers use different calculations to come up their results. No matter which meter you use for TDS readings, you should only take the results as what they are, an approximation.

These TDS meters use an internal conversion formula to display the EC level as an average ppm. In most cases, this comes out at a 700:1 ratio. This will mean that when you have an EC of 1, you then have 700 ppm. Other makers of these meters use 500:1 ratios for their calculations, and with this difference, it is easy to see why there is such a debate.

The safest route for growers is in using the 700:1 ratio and the reason for this being it is safer and better for your plants to add too little nutrients. If they begin showing signs of nutrient deficiency, then it is much easier to add more than to dial back the strength to a weaker solution.

To reiterate about nutrient strength during different stages of plant growth, you are far better to keep things simple and using nutrient solutions at half-strength during any vegetative phase, and then increasing them to full strength during flowering and fruiting stages.

To keep things on a level, it should also be standard practice to empty and refill your reservoir on a regular basis

The good news is, when you read EC levels, this will return the same results no matter who manufactures the meter.

EC Meters

Testing meters come with many names. They can be EC meters, CF meters, and Truncheon meters. These are all basically the same device, but in looks, they might appear very different.

Digital EC meters can take readings and do all the calculations for you internally. A Truncheon meter, on the other hand, does a reading, and on the side, there are 3 scales, so when the mark stops, you then have your three levels.

For new growers, these digital meters are the better option. They can be faster in operation, and although the Truncheon meter is manually read, it is a lot more expensive than digital.

When taking EC readings, this needs to be performed on a daily basis because things can change rapidly, and as we saw earlier, weather and ambient temperatures can play a large part in these changes.

Here are some simple use and maintenance steps for using a digital EC meter.

Maintenance of an EC Meter

  1. Always be sure to stick to the manufacturer’s instructions and recommendations
  2. Once you have used the device, always clean the electrode with distilled water and carefully dry with a lint-free cloth.
  3. On a regular basis, you should clean the electrode with rubbing alcohol. To do this dip and swirl around before giving it a good rinse with distilled water, and drying is as above.
  4. If there is any reason you need to store it for extended periods, always remove the batteries.

Using an EC Meter to Take Readings

  1. Remove the end cap which protects the electrode.
  2. Dip the probe into your reservoir and hold in place for up to 2 minutes or as advised by the maker of the meter. During this time, the meter will be reaching the same temperature as your nutrient solution.
  3. Once done, you can pull out the device and take the reading from the digital display. Many meters come with various buttons you can press to reach the other readings.

Organic Fertilizers and EC Levels

While reading EC levels can be very beneficial for your hydroponics system, when growers use organic fertilizers things can become very misleading. This is because the molecules in organic fertilizers usually don’t conduct any electricity.

Growers are still recommended to take EC readings with the aim of determining the soluble salt levels.

It is the case though that many of the nutrients won’t register on EC readings due to the form they are in. In most cases, they won’t have been broken down into simple salts. When readings are taken with EC meters, the gained results will more than likely read much lower than if they were using non-organic nutrients.

What growers tend to find is that although readings are lower, plants are showing no signs of deficiency. This means that nutrient profiles must be adjusted for use with these organic fertilizers.

Calcium can be one mineral which is lacking and can sit at around 100 ppm which is a long way from the recommended 200 ppm for leafy green vegetables. But, with the level at only half of the suggested, these leafy greens don’t show signs of calcium deficiency. One compound that can be added to rectify this is calcium sulfate.

It has been found both calcium and magnesium lacking when using organic fertilizers, but, if growers are using regular water, these deficiencies can be made up. However, this doesn’t help if you are using pure water.

Regular water contains 30 ppm of both calcium and magnesium, and over extended periods (several months) calcium levels naturally increase inside your reservoir, and can almost reach the recommended 200 ppm. Magnesium can naturally increase over time in the same way.

One thing which has been found when using organic fertilizers is that the smaller the reservoir, the more frequent testing must be carried out.

Conclusion

As you can see, on paper EC levels, look hard to control, but in reality, they are as easy to test for and to adjust as pH levels are.

Learning how to fine tune your hydroponic EC levels brings many more benefits than choosing to ignore it, and this can be evident when you have symptoms such as nutrient burn, or you are beginning to have vegetables with little taste.

All the formula are best remembered, but with a digital meter to take the readings, adjusting your EC levels works out to nothing more than dilution. As long as you can keep the EC levels on the right side, it is straightforward to adjust so your plants can grow to their full potential.