How to Keep Water Cool in Hydroponics: 8 Easy Ways

One thing growers should never overlook in their hydroponic system is the temperature of their nutrient mixture. As soon as the temperature reaches over a certain point, the solution can’t hold the dissolved oxygen as long.

Add to this, when there are unhealthy root masses mixed with these temperatures, it creates the perfect place for pathogens like root rot to take a foothold. To combat these problems, you need to make sure your nutrient solution remains between 65 and 75 degrees.

Here we will look at ways to cool your hydroponic reservoir and solution. While these can make the difference, some of these methods come with their own downsides when in use.

In summary, according to other sites such as NoSoilSolutions and Epic Gardening, here are the main eight ways to cool a nutrient reservoir.

  1. Keeping your reservoir in the shade
  2. Paint your reservoir to reflect light
  3. Increasing the size of your reservoir
  4. Top off your nutrient solution
  5. Bury your reservoir in the ground
  6. Making a swamp cooler
  7. Making your own cooling coil
  8. Purchase a water chiller

How Can I Cool My Hydroponic Reservoir?

Here we will take an in-depth look at the above methods. The first couple of entries in the list should ideally be done as a matter of course. Aside from controlling temperatures, they help prevent light entering and the growth of algae.

1# Keep Your Reservoir in the Shade

Any grower should be doing this one thing by default. Being able to minimize the amount of light which falls on your reservoir will help prevent it from warming up in the first place. Aside from this, you also need to be sure no light is entering your reservoir, this will warm it quicker, and it does allow algae to form along the water line.

2# Paint or Insulate Your Reservoir

There are two things you can try in this solution. The problem doesn’t just come from tanks, which are in a warm environment. Nutrient tanks can catch the heat from grow lights. As soon as this starts to hit the dark colors of your tanks, then the solution inside begins to warm up.

Solutions for this are to either paint your reservoir a light color as a way of reflecting the light and the heat, or you can cover your tank in a reflective insulation material. Even regular insulation can be enough to help maintain cooler temperatures in your tank, yet reflective insulation comes with an added benefit.

Once your grow lights hit the top of your tank, this reflective material bounces light back, which can reach the undersides of your plants.

In summary, here are things to know about painting or insulating your tank:

  • Don’t choose a light plastic to save on painting, this can lead to algae growth when light passes through
  • Dark plastics absorb more heat while light colors reflect
  • Reflective insulation helps cool, and throws light back onto your plants

3# Increase Your Reservoir Size

Depending where hydroponic gardens are located, this often dictates the size of reservoir in use. For small gardens, growers tend to go for a smaller tank to match, however, these warm up quicker than larger reservoirs.

If you add a larger reservoir, your nutrient mix becomes more stable. This doesn’t just mean you can keep lower temperatures, but also it helps balance pH levels, PPM and other concentrations in your mixture.

  • Small reservoirs fluctuate easier
  • Large reservoirs add stability for controlling temperature and other factors
  • PPM, EC and pH are easier to control in larger tanks

4# Top Off Your Solution

If you need a quick fix, then this can suffice to drop your temperatures down a few degrees on hot days. This method shouldn’t be used too often because either you will be diluting your nutrient mix, or you will be using more nutrients than you need to.

It is better to use this method in case of emergencies because if you have temperature fluctuations, they will always be there, and this method doesn’t do much to eliminate them.

  • Not to be used all the time
  • Add cooler solution slowly so not to shock plants

5# Bury Your Reservoir

This method only works if you have an outside hydroponic garden. You can prevent several problems with your nutrient tank by burying it. This helps to maintain cooler temperatures but using the natural coolness of the earth, and it is sure to stop any light from entering your tank.

The main things to remember with this method are you may struggle when you come to flush your tank between growing. If it is already under ground level, you may not have a suitable drain point.

6# Make Your Own Swamp Coolers

Swamp coolers are effective, and very simple to make. All it requires is to take a suitable fan and blow this across the top of your nutrient solution. As a result, you may see temperature drops of around 5 to 10F.

The downside to this is you can be topping off your reservoir more often to compensate for evaporation. Second to this, your EC and PPM levels will rise that will require continual adjustment. You may also find using this method, you are allowing light into your tank.

7# Make a Cooling Coil

While these can be effective, they do take more work and they have the downside of wasting water. To make one of these, you can take copper or stainless steel tubing and form it into around 20 coils. This will then sit inside your reservoir with a hose connected to both ends.

One fits on the faucet while the second drains. In operation, the water trickles through the tubing and will pull heat from your reservoir into the liquid inside.

  • Wastes water
  • Can offer unlimited cooling at a cost
  • Doesn’t need any power

8# Buy a Water Chiller

One of the most efficient ways to cool your reservoir is to purchase a water chiller. These deliver a hands free approach and give you lots of control. These do become more cost-effective if you have more than a couple of tanks where you need to control the temperatures.

These water chillers can be a hefty investment, and they do consume electricity for their operation. There are varying sizes so scaling up to any sized garden can be straightforward.

  • Most expensive option
  • Still requires water pumps
  • Can be a set it and forget it solution
  • Ideal for larger gardens

Ideal Hydroponics Temperature 

Plants thrive better when they are in a constant environment. While nutrient temperature can fluctuate, the main problem can stem from the grow room itself.

For ideal temperatures for good plant growth, the surrounding environment should be around 70 to 80F. For optimum root growth, the ideal temperatures of the root zone should be around 66F. 

Once the temperatures are above these, then stress starts to show in your plants. Heat stress can cause plants that are spindly in the early stages of growth, and mature plants can fail to fruit or flower correctly.

Most of the above methods focus on cooling a nutrient mix which is already warm. However, to have the perfect grow room will mean that your tanks temperature doesn’t climb in the first place.

Here are some of the best ways you can help maintain your grow room environment.

Air conditioners: This works as well as a water chiller, but for the surrounding environment. The environment will warm because of grow lights, or any natural light, which spills in through windows. You can purchase window type air conditioners that are ideal to cool your grow room enough without breaking the bank.

Relocate or Insulate Grow Rooms: The biggest culprit for tanks heating up will be your grow lights. If your grow room faces the south, or your grow room is under a hot roof, you may be fighting a losing battle with your tank temperatures.

Insulating your grow room can prevent hot weather having an impact. Additionally, if you can move a grow room into the basement, you will find it is naturally cooler than above ground level.

Increase Humidity: If your grow room suffers from low humidity, then your plants will take up more water to keep cool. This is where your tank levels drop faster and thus warm up quicker. Misting your grow room can keep plants and the surrounding areas cool, and as a result, your nutrient mix will remain stable.

Improve the Air Flow: Plants require good air circulation for healthy growth. This will also help prevent your nutrient mix from warming in the first place. Plants will benefit with circulating air, and it stops pockets or warm zones from forming around the grow room.

Run Lights at Night: One-Way of cooling a grow room which many growers often overlook is using their grow lights at night rather than in the day. Using supplemental lighting at night not only offers cheaper electric in some cases, but a grow room will be cooler at this time. The overall temperature of the room may not reach a level that will push your reservoir up to the higher limits to cause problems.

However, doing this will mean you need alternative counter measures in the day to cool your grow room. This will depend on the location as to the extent you need to go. If your grow room has access to natural light, it can be just a matter of extra shading, additional misting and fog to keep lower temperatures.

Calculating the Size of Water Chiller

One of the most crucial factors when choosing a water chiller is how well it will perform on your system. It isn’t just a matter of choosing one and expecting it to cool sufficiently. When it comes to the sizing of your water chiller, the following method allows you to determine the size of chiller unit that is sufficient for your garden system.

  1. Calculate your system volume – this includes all buckets and tanks
  2. Run your system with everything turned on – all grow lights, fans, etc.
  3. When your grow room has reached its max temp, take a reading before cooling your system using ice packs or frozen plastic bottles of ice.
  4. When your system mix cools, remove the ice and run for another hour.
  5. After this time, take the water temperature
  6. Subtract your ending temp from the starting temp
  7. Use the formula to find the minimum BTU required.
  • System volume: 80 gallons
  • Desired Temp: 65F
  • Running Temp: 76F

Formula: 80 x 8.34 x 11 = 7,339 BTU (gallons x weight of water x temporary difference).

A water chiller should run around 20% above your BTU requirement minimum to counteract performance loss.

Pros and Cons of Using a Water Chiller in Your Garden

Like many things for your hydroponics system, there are pros and cons of using a water chiller.

Pros of Hydroponic Water Chillers 

  • Cooler temperatures enable your solution to hold a higher degree of dissolved oxygen. This is the key basis of increased nutrient uptake and explosive root growth.
  • Highly oxygenated environments, which come with cooler temperatures, can help deter pathogens from taking hold.
  • A cooler reservoir will act as a heat sink in your grow room. This can draw ambient heat and help to cool the whole room

Cons of Water Chillers in Hydroponic Gardens

  • Expense is one of the largest primary cons for a water chiller. Although you can find affordable models, it can still be a cost that many growers can’t justify.
  • Noise – in operation, these will sit outside of a reservoir like air pumps. They will make the same sort of noises as air conditioning units.
  • Heat: Water chillers do generate heat when they cool water. Either they require ducting to transfer this heat out of the grow room, or they have to sit outside the grow room to not introduce more heat.

Why Do Roots Need Cool Temperatures?

Root zone temperatures affect overall shoot growth. Not only this, the impact from the root zone temperature will have more of a bearing on development and overall growth than the ambient air temperatures.

This occurs because the tissues of the roots send messages to the shoots. This will have an effect of how the shoot reacts to the environment. Growers see that there are many functions that occur for the plant in the roots, and thus, the root zone temperature becomes crucial.

Such is the effect of this, even thirty minutes of heat buildup in your nutrient mixture and in the root zone is enough to have a negative effect on your plants. One thing to note is that a daily cool average isn’t sufficient to counteract this.

As soon as your temperatures rise above 86F, then crops, which are sensitive to heat, will quickly falter such as lettuce or parsley.

When you look at something such as lettuce, the cooling of your nutrient reservoir does allow these crops to face higher than usual/ optimal temperatures above the surface.

While there are many biological happenings because of cooling roots lower than the ambient air temperatures, it is easier to know it reduces heat stress in the leaves of plants.

Root Zones and Different Hydroponic Systems

Cooling your nutrient solution to the optimal temperature isn’t all the equation. The remainder comes from the types of system you are running.

The root zone temperature needs to remain the same all the time. The cool mixture has a big influence on this, yet the system type and how it is built can affect this dramatically. A good example being the only system, which will have the same temperature root zone as the nutrients, will be a DWC system.

The roots are in constant contact with the solution. In all the other types of system, there is a degree of separation between the root zone and the reservoir.

A good example of how this can affect plants is in an ebb and flow (flood and drain) system. As your cool solution rises in the flood tables, the plants gain the advantages of oxygenated water and the roots are comfortable because of the lower temperatures.

However, things change as the cycle stops and the solution begins to drain back into the tank. Warm air from the grow room can be pulled through the growing medium as the solution drops. If the environment is warm, it can heat up your root zone considerably until the next flood cycle.

Unless you have a good means of cooling your solution, this will transfer heat back into your tank and thus warming it with each fill and drain cycle. Depending on your cooling solution, you may find that this is insufficient and as much as you are trying to cool your water, it increases in temperature regardless.

Not only will your water increase in temperature but also the root zone can be at a damaging temperature between your flood cycles.

Size of Your Hydroponics Reservoirs

One of the first things to be sure of is that you have a large enough reservoir. Rather than just being large enough for the size of system, you have, you are better to have a much larger one than you require.

Hydrotek, who are one of the largest names in hydroponic equipment recommend the following for reservoir sizes:

  • Small plants – ½ gallon for each plant
  • Medium plants – 1 ½ gallons for each plant
  • Large plants – 2 ½ gallons for each plant

Hydrotek recommends you choose a reservoir that is at least double the size.

You also need to consider how thirsty your plants will be. This can use your water and nutrients faster, such as is the like of tomatoes in comparison to lettuce.

This will use your mix faster and thus cause a warm solution once the level starts to drop.

Using all the above information can help to maintain cooler temperatures for your nutrient solution. However, if you find your grow room comfortable for yourself as you are working in that environment, then you are halfway to knowing how it feels for your crops.

9 Flowers to Grow in Hydroponics (with pictures)

Why Hydroponic Flowers?

Flower gardeners spend countless hours tilling and tending to the soil. This makes flower gardening appear hard work, and if it takes this much effort, then why would you consider growing plants in a hydroponic system?

There are in fact several benefits and advantages flower gardening in hydroponics has over soil growing.

Results come much faster, you can tailor your nutrients to each plant species, and you have no weeds, insects and less disease to contend with. This delivers an up to a fifty percent faster growth in flowers, and yields are much greater than compared to soil growth.

With this in mind, you can now grow flowers all year round, and which can be expensive to purchase when out of season. You can also have as many cut flower displays around your home as you wish.

Before an in-depth look at each flower, here are nine of the best flowers you can grow in your hydroponic system.

  • Peace lilies
  • Hoya
  • Snapdragons
  • Dahlias
  • Rex begonias
  • Carnations
  • Orchids
  • Petunia
  • Zinnia

Top 9 Hydroponic Flowers

Peace Lilies

As an indoor plant, the Peace Lily can be one of the easiest to care for. You need the right growing conditions though. These tropical flowers are part of the Spathiphyllum family and are recognizable by their dark green leaves and white flowers.

While we can grow these in a hydroponic system, they don’t like to be over-watered. They can in fact be more tolerant to under watering than being around too much water. Peace Lilies, which grow in a hydroponic system, are often adapted versions where they send out small roots to absorb water. Here you can see Peace Lilies grown in small aquariums.

Many growers often wait until leaves show signs of wilting before watering, this can prevent over watering. If they are over watered, it can lead to root rot, and the plant will suffocate.

Tips for Growing Peace Lilies Hydroponically:

  • Peace lilies like a temperature range of 68 F to 80 F. This will deliver optimal growth.
  • Clean leaves and you can reduce the risk of pests. The most common being aphids and mealybugs. 
  • Be sure to keep your lilies in warm draught free areas
  • The ideal pH range would be from 5.6 to 6.5.

Fun Facts about Peace Lilies

  • Despite the name, peace lilies aren’t related to true lilies.
  • NASA studied Peace Lilies because of their air-purifying abilities. They show them to be effective at removing formaldehyde, carbon monoxide and benzene from the air.
  • All parts of the Peace Lily plant can be poisonous as they contain calcium oxalate. If ingested in sufficient quantities, this can cause respiratory and stomach irritation. You should keep away children and pets from Peace Lilies.
  • Indoor varieties can grow up to around 16-inches while outdoor types can grow up to six feet in height.


Hoya plants are better known as the wax plant. These are a vine, shrub, and evergreen perennial creeper. When flowering, they adorn some gorgeous star-shaped flowers with leaves that can either be smooth or feel like soft felt. Hoyas are very low maintenance, which is one reason they are so popular for a houseplant.

Hoyas are another plant that doesn’t take to over-watering. Depending on the growing conditions, Hoyas can have flowers 1/4 inch in diameter up to 4” in diameter. There are many different Hoya’s choosing from, 200 species to be exact, and they all boast their own unique colors and shapes. So choosing the hoya, you desire is half the battle to growing and nurturing them.

Tips for Growing Hoya Hydroponically:

  • When pruning, avoid cutting the long tendrils, these are where flowers develop.
  • Hoyas require adequate drainage so they are not accidently over watered.
  • Likewise, this tropical plant can absorb moisture through the air, which is what makes it so low maintenance. Consider a system that uses humidity.
  • Hoyas prefer bright indirect light. What they don’t like are dark corners or direct sun. Hoyas can handle cooler weather from 50 degrees F up to warm temperatures of 77 F.
  • Maintain a pH range of 5.0-6.5

Fun Facts about Hoya

  • Even though there are over 200 different variations of hoya, you won’t find blue, purple, or violet colors represented.
  • Some species of Hoya have a Crassulacean Acid Metabolism
  • Each cluster of flowers on this plant can contain up to 40 individual flowers.


The botanical name for Snapdragons is Antirrhinum and means ‘like a snout.’ This plant is native around Europe and North America. They have become a popular favorite because of their vibrant hues, and their flowers that resemble a dragon-like mouth when pressed.

Mature Snapdragons can grow from 6 inches up to 48 inches depending on the variety, and the growing conditions. This means you may require some support for your plant, and the growing medium will need to hold them firm. Perlite is often the more common.

Even when grown in a soil-based medium, it’s common to grow flowers like snapdragons indoors before transferring them. This is because they are very sensitive to weather conditions. There are over 18 different snapdragons, and all these deliver bloom colors of pink, yellow, red, white, purple, peach, orange, and bi-colored.

Tips for Growing Snapdragons Hydroponically:

  • Snapdragons need adequate watering but not standing in moist conditions. Your growing medium will need to dry between cycles.
  • Snapdragons are perennials that require full sun with only occasional shade.
  • They prefer pH levels between 6.2 and 7.0.

Fun Facts about Snapdragons

  • Often called Dog’s Mouth, Lion’s mouth, Dragon flower and more depending where you are.
  • The leaves and flowers have some anti-inflammatory abilities.
  • We can apply them as poultices for ulcers or tumors
  • When snapdragons are mixed with tea, they can help detoxify the blood and increase urine production to clear the body from waste.


Dahlias are closely related to sunflowers, daisies, zinnia, and chrysanthemums. We know dahlias as octoploids, which means they have eight sets of homologous chromosomes.

If you grow these in your hydroponic system, you will need to be sure they have lots of space. As you are planting in a container, this does need to be at least 12 inches deep. Some varieties require deeper which can rule these out of your system. Dahlias grow half as wide as they do tall; so lateral space is important.

Dahlias like to have lots of light, and they are thirsty feeders. Your growing medium should dry out between watering schedules, and you will need to monitor your tank levels. Once planted, you will need to fertilize with a 10-10-10 NPK mix.

Tips for Growing Dahlias Hydroponically:

  • Dahlias need constant light to bloom and grow. It’s recommended that they receive a minimum of eight hours daily.
  • Dahlias are spring-planted flowers. This means they prefer warmer temperatures. Stick to a minimum of 60-degree temperatures and a maximum of 72 degrees.
  • If you prefer your dahlia’s being shorter and bushier, cut the center shoot above the third set of leaves to encourage shorter growth
  • Dahlias need a pH level range of 6.5-7.5.

Fun Facts about Dahlias

  • There are over 20,000 cultivars of Dahlia.
  • It’s the official flower of Seattle, WA although they are not native to the area.
  • Dahlias were known as a vegetable in the 18th century but later became more known as flowers.
  • They named them after 18th-century botanist, Anders Dhal.

Rex Begonias

Rex Begonias are unique in every sense. We do not know them for their flowers, rather their leaves and foliage. This is colorful and can be overlaid onto the thick fibrous leaves. It is possible to find a myriad of color options from maroon, lavender, gray, silver, pink and reds.

Rex Begonias were first noted in 1856 when a shipment of orchids to England included the mysterious plant that no one could identify. This plant is tropical and native to South America, Africa, and Southeastern Asia. There are over 1,831 species of begonia, each with their own intricate and original leaf appearance.

Tips for Growing Rex Begonias Hydroponically:

  • Since Rex Begonias are tropical and subtropical plants, they are native to jungle types of environments. It is this, which makes them great as houseplants as they require little light and prefer shaded and cool areas.
  • These plants can grow from 12 inches to 24 inches in height. With leaves growing an average of 4-5 inches, it is also crucial to be wary of outward growing space requirements.
  • You can tell when the Rex begonia has received too much light, as the foliage will turn brown.
  • Stick to temperatures between 60 and 85 F.
  • Maintain a pH range of about 5.7 to 6.2 for optimal growth.
  • Rex Begonias like humid conditions; this may mean misting their leaves early in the day.

Fun Facts about Rex Begonias

  • You can propagate Begonias by using stem cuttings.
  • The Begonia stem is actually designed to store water so that during dry periods of the year, the Begonia remains hydrated.
  • Begonias only have a life span of about 2 to 3 years on average. They can live a few years longer if they live in an excellent and nurturing environment.
  • The juice of the begonia plant is thought to relieve headaches and as an eyewash for conjunctivitis.


Carnations are by far one of the most popular flowers to be grown in hydroponic systems. They are also one of the most commercially grown flowers because of the number of individuals who have them as indoor decorations.

Carnation petals have a fantastic aroma and make any room feel inviting when they have a presence. On top of this, the leaves can also be edible and are sweet to the taste. Growing from cuttings is often the preferred method. If propagating in soil, it can take between two and three weeks when from seeds. Hydroponics can speed up this process.

Tips for Growing Carnations Hydroponically:

  • Make sure carnations receive 5-8 hours of uninterrupted sunlight daily.
  • Carnations will thrive the best with a pH level of around 6.0.
  • Rockwool starter plugs are ideal for seedlings up to 4 to 5 inches in height, at this stage, we can transplant them.
  • Keep the temperature range of 65 to 75 F.
  • Ebb and Flow, Dutch bucket or DWC systems are best suited to Carnation growth. They will need support when they grow.

Fun Facts about Carnations

  • Carnations are believed to be native to the Mediterranean area. However, because of extensive cultivation over the last 2,000 years, no one knows for certain where their origins lie.
  • Annual carnations, border carnations, and perpetual flowering carnations are the most common types that are grown.
  • Greeks and Romans used carnations in garlands.
  • Carnations are a bisexual flower. This means they have both male and female reproductive structures that inhibit better growth and production.


For many people, Orchids are among the most beautiful flowers there are. Around the globe, they are a gardener’s favorite thanks to their woody-thick roots and colorful blooms. One thing many lovers of this plant are unaware of is, around the world, most of these are actually grown in hydroponics systems.

The reasons for this that where these Orchids grow in tropical climates, they latch themselves to tree bark or in between rocks. As the climate can be wet, it exposes them to sufficient watering from the rain. Once the rain stops, it exposes the roots to the air and can have plenty uptake of oxygen.

Add to this surrounding organic matter which rots, and they have a steady stream of nutrients. This is hydroponics in its purest form, and it is what makes growing Orchids in a proper system so easy and so rewarding.

Tips for Growing Orchids Hydroponically:

Fun Facts about Orchids

  • The flowers on orchids can survive for up to 6 months.
  • Out of the millions of seeds that orchids produce, less than a hand full will develop into a plant.
  • Orchid seeds do not contain endosperm, which is what they need to provide nutrients during germination. Because of this, they require symbiosis with fungi to achieve germination. Germination of orchids can sometimes take up to 15 years.
  • They use orchids in the perfume, spice, and medicine industries.


These popular South American flowers can withstand hot climates. They are widespread around many gardens in borders and in pots. There is an almost endless range of colors available, which is one reason they are gardeners favorites.

Most Petunias you see for sale are hybrids and are developed for specific purposes. As they grow, they can reach anywhere from six inches to four feet in height and have a spread of up to three feet. This means you will require support and lots of spacing to avoid overcrowding.

Tips for Growing Petunias Hydroponically:

  • Petunias need at least 5 to 6 hours of full light to thrive at their best.
  • When fertilizing Petunias like a balanced mix of 8-8-8, 10-10-10 or 12-12-12.
  • In germination, your Petunias will prefer warmer temperatures, however, once they have germinated, move them from this warm area so they can grow in cooler areas. They prefer cooler temperatures between 57 and 65 degrees Fahrenheit.
  • Petunias like pH levels of 6.0 to 7.0.

Fun Facts about Petunias

  • Petunias are an annual plant, so a full life cycle takes one year.
  • Common Petunias are edible and have a sweet and spicy flavor
  • There are four groups, which all Petunias fall into. Grandiflora, Multiflora, Milliflora and Hedgiflora.
  • Petunia comes from the word “Petun” which means tobacco in Brazil. These two plants are related and can be crossbred.


Zinnia are easy to grow and are a part of the daisy family. Being native to Southwestern United States and South America, they like to grow in full sun. At least six hours of full sun or bright light are recommended to get the best of these colorful plants.

Once they grow, they can range between 4 and 40 inches in height. This means you will require some support and a growing medium that can support their root system.

Their large range of bright colors and ability to withstand hotter climates makes them popular for planting in many a garden environment. Zinnias will reseed themselves each year. When selecting from the many varieties for your hydroponic garden, you will be better off selecting the more compact varieties.

Tips for Growing Zinnia Hydroponically:

  • Keep the temperature range between 74 and 84 degrees Fahrenheit. They can grow in temperatures as low as 60 degrees Fahrenheit.
  • Zinnias like moist environments yet they don’t like to be over-watered because they can fall foul of root rot. It can cope with dry spells better than standing in water
  • Once flowers show, they can benefit from 5-5-5 fertilizer for larger blooms.
  • Zinnias prefer pH ranges between 5.5 and 7.5.
  • Zinnias like a lot of light, but they can do just well in environments that receive less than 6 hours of light minimum.
  • If you want bushier plants, you can pinch the growth tip of the plants when young. This creates shorter side branching plants.

Fun Facts about Zinnia

  • Zinnia leaves have a sandpaper-like texture to them.
  • They named them after the German botanist Johann Gottfried Zinn.
  • They can have a single, semi-double or even double layers of petals.
  • Removing dead or faded flower heads, you will see an increase in flower production. We call this dead-heading.
  • Butterflies love Zinnia’s, and you’ll find an abundance of them attracted to your garden if you plant them outdoors.

How to Get Rid of Algae in Hydroponics for Good!

Algae can cause major problems in hydroponics systems. It can build up and cling to any surface. This means there isn’t any system that can be safe from it once it gets a foothold. It sticks inside tubes, it can work its way into pumps, and it can bring a system to its knees.

Once it begins to decompose, it can bring with it a horrible odor. However, it is when you have a heavy infestation things get worse. This mass of algae can form a barrier against your growing mediums.

When this begins to happen, two significant things will happen. First is the precious nutrients are depleted from the system as the algae uses them itself to grow. Second, there is a severe drop in the dissolved oxygen in the system. This causes your plants to start suffocating, and means they are weaker to fight off any other pathogens.

What Is Algae and How Does it Get Into My Hydroponics System?

Algae is a simple, plant-like aquatic organism that can grow in just about any aquatic environment. Because they are so similar to plants, they require the same basis for growth; sunlight, water, and nutrients.

Algae can be an incredibly versatile and durable organism and can take hold wherever there is a minimal amount of these three basics. It’s because of their similar needs to the plants you are trying to grow in a hydroponics system that makes them difficult to prevent and address once they’ve arrived. You can’t starve them of their needs because your plants also need the same things.

In terms of how algae ever reaches your system in the first place, that is also explained by the versatility and durability of algae as an organism. While you might think that, your system is sterile, well contained and free from potential contamination sources during the setup process, algae can, and likely will, find a way into your system.

Algae gets into hydroponics systems through microscopic airborne spores. Because these spores can be so durable, it can be almost impossible to prevent them from getting into your hydroponics system. Many growers try to fathom how they get algae in their system when they have a sterile environment. The spores from algae can be carried by the wind, and it only takes one to latch onto your system. Growers themselves can even be a carrier of spores without realizing.

Once in your system, algae finds the perfect conditions for growth – assuming you’ve set up a system that’s also perfect for the plants you’re meaning to grow! This is why algae can be so problematic. They are almost impossible to keep out of your system, and once they find a home in your system, they populate incredibly rapidly.

In this light, you should expect some level of algae growth within your system. Keeping a completely algae free hydroponics system is essentially impossible, and therefore, should not be the goal you’re aiming for.

By acknowledging that come amount of algae will be present, the focus of your efforts should be to prevent it from getting out of control and overtaking your system. While a healthy system can cope with small amounts of algae, as soon as the levels increase, it will be time to harvest your crops and take drastic action before starting another growing session.

By focusing your efforts on preventing algae growth getting out of hand, you can help to make sure that algae growth remains at an acceptable level. Any strategy for algae problems should be with control rather than complete prevention, because this can be nearly impossible to do.

How to Clean Algae Out of Your Hydroponics System

A lot of this will depend on the stage of your system, you may already have an infestation, or you are building a new system and want to prevent algae from occurring. Either way, it is better that you understand what causes algae, and how you can prevent it from taking hold.

Two things to note are that algae doesn’t grow on dry surfaces, and preventing as much light as possible from reaching your nutrient solution can help minimize the risk of an algae outbreak. All your channels and conduits will have covers, which prevents light from entering. Likewise, your media beds or pots can be covered to prevent light from hitting the surface.

Growers who face algae infestations may be tempted to turn to a commercially available algaecide. While these appear to be a good solution to control an algae problem, they are in fact of very little use.

An algaecide can help to control the blooms of algae, yet, if they are misused or overused, they can damage your plants delicate rooting systems. This is more the case if your plants are small, and have not long been planted into your system.

The worst thing with these commercial products is that once they are used, they weaken in the system, and then the algae just begins to grow again. This means you need more of the product, and you end up in a cycle that shows no end.

The first thing you’ll want to do is to assess the amount of algae in the system. If it seems to be a small amount, you need to determine where this is getting into your system. It could be some light finding its way into your reservoir, or into another part of your system.

If it doesn’t become worse or affect your pump and air stones, you may be able to tackle the problem with some preventative measures until you come to the end of your growth cycle. At this stage, you can go through the following to give your system a thorough clean.

The following steps explain how to give your system a full clean. This can rid it of any traces of algae before you commence your next growing cycle.

System Clean and Sterilization

Because of how easy algae spores can be passed around via the air, it will be important to give your growing room a good clean as well as your system. There will be little benefit in cleaning your system to find you are up and running, and there are algae spores lurking on the walls or your lighting systems.

It will be your system, which is more important because it is this that is in direct contact with your plants. Growing medium and pots need their own cleaning, also if you are using clay pebbles, (Hydroton) be sure this doesn’t dry out and stays moist.

Step #1 Draining the System

Ridding your system of the old nutrient mix will be the first step. Some systems may not be using pumps; this would mean manually emptying your reservoir. If you have a recirculating system, then there are two ways to drain your tank.

If your tank has a drain valve, you can open this and let the water run out naturally. However, you will need a run off area, which is lower than your tank. If you are using the pump return method. Be sure to isolate all the electrics before removing the pump from the tank.

Remove the outlet pipe, and then connect the female connector onto the pump. You can now feed the outlet hose to your desired drain point. This will remover the water via the pump rather than naturally draining.

Once you reach the lowest point before the pump begins to run dry, you will need to turn it off. This method and the other will have a couple of inches of water remaining. Manually remove this using a sponge and a bucket.

Step #2 System Cleaning

Even though you are tackling an algae problem, these steps will be the same for a system clean after each harvest. This can be one way to be sure you have eliminated any traces of algae, pathogens or bacterial growth.

You can use two chemicals at this stage:

Food Grade Hydrogen Peroxide: This should be a 35% concentration. 3 milliliters (mls) for each gallon of water.

Unscented Bleach: The ratio of this should be 1:100. This would work out as 1.3 oz. to each gallon of water.

  1. Drain your system by either of the methods mentioned
  2. Remove pumps and air stones, these may require cleaning if algae growth reaches that far
  3. Remove any parts of your system which are hard to access
  4. Check for debris, broken roots and further algae growth
  5. With your cleaning solution of choice, use green scrubbing pads and wipe down all the areas where you see algae growth. Bottlebrushes can be used for hard to reach areas.
  6. Wipe clean and then assemble any system parts you dismantled
  7. Fill your system higher than usual as this covers the line where the algae was forming
  8. Add your sterilizing solution (bleach or hydrogen peroxide)
  9. Run your system for between 4 and 6 hours
  10. Scrubbing channels and conduits will flush this algae and debris back into your tank
  11. Drain your system and rinse with fresh water. Be sure to remove all the debris
  12. If using bleach, you need to triple flush your system
  13. Drain a final time and wipe down with clean towels
  14. You can turn on your lights as this can stop any algae starting to form and residual water

System Components

Although the algae may not be growing on your pumps or air stones, there may be traces on your growing medium and the pots. To clean all of these including pumps, the recommendation is to use hydrogen peroxide. You can though use a bleach bath to soak all of these small components. This will be a 1:1 mix, and you still need to carry out a triple rinse to remove all traces.

How to Prevent Algae from Growing in Your Hydroponics System

Algae growth in hydroponics systems is unavoidable to come extent. Anytime you’re working with nutrient rich water and sunlight, you’ll have ideal growing conditions for algae. As these are, the two main essentials needed in algae growth, and because you can’t avoid having a nutrient rich water solution, the best prevention method is to cut down on light exposure.

The best way to prevent out-of-control algae growth in your hydroponics system is to reduce your reservoir’s exposure to light as much as possible. This can be easier said than done, but there are a few ways to help with this.

  • Use Opaque or Solid Colored Materials
    One way to cut down on the potential light exposure is to use opaque and solid colored materials wherever possible. This will help prevent any light from penetrating into these parts of the system, thus reducing the potential for algae to photosynthesize and grow.
  • Cover All Exposed Water
    This step is similar to the previous step in that it’s predicated on prevented algae from ever getting started in the first place. Again, if algae can’t receive light to photosynthesize, it can’t grow and populate within your reservoir.

    There are a number of ways to cover your water, all of which depend on how your system is set up. For smaller rigs, it might be as simple as using a solid colored material to build your plant supports into. In larger systems, you may need to fashion a sort of tarp or plastic cover with holes cut out for your plants to grow through, but that covers all other areas.

Alternative Options for Preventing Algae Growth

While the most effective way to prevent algae growth in a hydroponics system is to cut off any potential light sources, there are a few alternative measures that growers can take to avoid this nuisance. These options vary in their effectiveness but can have good results when applied properly.

  • UVC Light
    One method for this is to install a UVC light in your water filtration system. This light will help to kill and eliminate potential microorganisms, algae included, that could have found their way into your system. This can be costly, and they will need to be powered as long as your system is running. However, if you have serious problems with algae, a UVC light can be a good solution.
  • Grapefruit Seed Extract
    Some studies have found that grapefruit seed extract in the correct dosages can be an effective measure for killing and preventing algae growth. Grapefruit seed extract is a powerful anti-parasitical, anti-bacterial and anti-fungal compound. When used in low doses, it has been proven to very very effective in hydroponic systems while not being toxic to plants. The dosage recommendations will be around 5 to 10 drops per gallon of water in your system. This can be sufficient to prevent algae growing.
  • Barley Straw Rafts
    This solution should only be considered if growing on a large scale in a larger rig but has also shown effectiveness in fighting algae growth. Studies have found that the aerobic decomposition of barley straw release a chemical solution which inhibits algae growth. Again, this is a slower process, and isn’t ideal for smaller growers. You do need to be sure there is lots of dissolved oxygen in your water so only aerobic decomposition takes place. You can now purchase liquid barley straw extracts for use in the prevention of algae growth, but you do need to be careful of the amount of algae death as this can reduce the amount of dissolved oxygen.

No matter which method you use to clean and control the growth of algae, in your hydroponic system, there is nothing better for prevention that limiting light exposure onto your nutrient mixture.

Algae and pH Fluctuations

One area not mentioned is how algae growth can have a severe impact on your pH levels. While methods such as ebb and flow systems are more prone to algae growth, there isn’t one system that will be free from it forming.

Algae is resilient and as soon as the conditions re almost ideal, it will get a foothold and can lead to issues. In this case, pH fluctuations. Algae uses carbon dioxide in the same way as plants, this coupled with nutrients and light help produce photosynthesis during daylight hours. As this period nears its end, the pH will usually be at its peak.

During night hours, the opposite happens. It is here the algae consumes dissolved oxygen from the water to release carbon dioxide. This itself is released back into the water via respiration. The problem here is this carbon dioxide will create carbonic acid, and as such, it causes a drop in pH levels.

These swings do nothing but cause more problems as they progress. Plants can end up suffering from nutrient lockout, or they can slowly drown through lack of oxygen in the water.


Because there is no way you can eliminate the chances of algae from forming, it is better to expect its presence and take precautions to limits its exposure. By following all the above, you stand the best chance of being algae free, and having a system, which performs at, is best.

Prevention is the best medicine because if nothing else, it will save hours of cleaning to eliminate the same problem repeatedly.

Learn How to Keep pH Stable in Hydroponics

Testing water pH

When new growers first start a hydroponic system, they often hear terms that sound confusing. One of the hardest to fathom is the pH, while you may not fully understand it in the beginning, it is something, which in theory can be learned quickly.

In summary, to keep pH levels stable, it can take a few steps and a little effort from the grower. These are the key areas you need to understand.

  • Delivering the right supply of water
  • Performing water treatment methods in response to the tested levels
  • Understanding how the addition of nutrients can affect pH levels.
  • Understanding what pH levels your given plants require

When you begin to understand what pH levels are, you quickly learn that they will never remain stable on their own accord. There are too many variables, and many external influences that will change the pH level.

It does take effort to monitor and alter your systems pH; however, this isn’t hard once you understand the core principles.

To know what pH means to your plants, and how it can affect their growth is the first area you need to understand. After looking at what pH is, we will see how it affects your system, and how you can maintain the correct levels.

What is pH?

First, up, there is a scale that runs from zero to fourteen. Every liquid will have a different reading against this scale. Plain water as an example has different pH levels depending on the source. Plain water from the faucet will have a different pH to the water in your system; this is because in many cases it is better not to use faucet water when possible.

This scale has zero, which is the most acidic, this runs up to the top (number fourteen), and this is the most alkaline. Most living things like a middle of the road balance, so this is around 7. Not only is this a good starting pH for most plants to thrive, but it is also the right level for the human body.

For plants to thrive at their best, they do favor pH levels, which sit around 5.5 to 6.5. Nevertheless, there are some plants and vegetables which like to go the other side of neutral to a pH of 8. Alkaline substances are soluble salts made up of potassium and sodium carbonate. Alkaline is the scale of the alkali within the solution.

When you have favorable pH levels in your system, this enables your plants to take up all the micro and macronutrients through the root systems. Add to this, you see faster growth in your plants because they have an increased intake of NPK (Nitrogen, Phosphorous and Potassium).

To go further in depth on this matter, you can head over to the pH levels Wikipedia page for a detailed breakdown of what these levels mean. This may appear interesting, yet it reaches a little outside what you need to know as a grower.

Acidic Solutions pH Alkaline Solution pH
Battery acid 1.0 Blood 7.35 – 7.45
Gastric acid 2.0 Hair shampoo 8.0
Lemon juice 2.4 Sea water 8.0
Cola 2.5 Permanent wave 8.5 – 9.2
Oxygenated water 2.5 – 3.0 Hand soap 9.0 – 10.0
Vinegar 3.0 Hair dye 9.5 – 10.5
Orange or apple juice 3.0 Magic straight 11.5
Beer 4.5 Household ammonia 11.5
Coffee 5.0 Household bleach 12.3
Milk 6.6 Household lye 13.5
Pure water 7.0 Drain cleaner 14

One thing, which is worthy to note, the closer you get to each end of the scale, and the liquids will burn. It doesn’t matter if it is acidic, or alkaline, so you will need to take caution when dealing with any pH level treatments.

Why pH Levels are Important in Hydroponic Systems?

We have seen when pH levels are outside the ideal range for your plants, they run the risk of not absorbing enough nutrients to help them grow. On top of this, it also helps you understand how soluble the salts are in your nutrient mixture.

Every mineral has a different tolerance when it comes to the respective pH level. As a rule of thumb, plants need high amounts of macronutrients. If the pH level is too high or too low, then these become immobile, and it is this that restricts their uptake, and leads to nutrient deficiencies.

Micronutrients on the other hand are required in smaller doses. These will be affected on either end of the pH scale. Once your pH is too low, then this means your plants can absorb too many as they are highly soluble. This doesn’t lead to nutrient deficiency; it actually leads to a solution that is toxic to your plants. If you go to a pH that is too high, then you will see a deficiency in micronutrients.

One of the first signs you need to be aware of is young foliage, which is yellowing or pale in color.

In order to keep the pH levels balanced in your hydroponic system, first, you really need to understand the elements that will affect the pH levels.

Growing Medium

Almost everything can affect your pH level in your system. One of the most significant areas will be your growing medium. A good example being calcareous rock, this will release magnesium and calcium into your solution. As soon as they leech into your water, you will need to adjust. Luckily, this isn’t a common growing medium.

Coco coir is very popular, and this can affect pH as they contain sodium chloride. Because of this, this needs to be soaked thoroughly to wash out any residual contaminants.

One other common growing medium is perlite. The pH of this is between 6 – 8, this means it can be added with no significant pH swings in either direction. Rockwool is another favorite and has a pH of between 7 – 8.5. This does require washing before use and an adjustment of the pH once it is in your system


There is a lot to learn about solution temperatures, so without going into too much detail hydroponic solutions should be around 65 to 80 degrees Fahrenheit. If it gets much warmer than this, water starts to evaporate faster than the mineral salts.

One this happens, these begin clinging to the side of your reservoir, and thus increase nutrient to water ratio. You can also find that systems, which have smaller reservoirs, suffer more than a larger reservoir. Depending the region you live, you may require either a water heater, or a water cooler to keep your mix at the ideal temperatures.

Plain Water

Hydroponic systems need a sterile environment to function at their best. Water from the faucet isn’t recommended because of the amount of treatment it has been through. Different regions can have hard or soft water, so the base pH will never be standard.

It is a recommendation to use distilled or reverse osmosis water when possible. If this isn’t readily available, you can purchase these reverse osmosis kits which sit in your plumbing system. While these can seem to be a small investment, they can pay for themselves over time.

Here is an example of a reverse osmosis filter system. It can deliver pH neutral water for drinking, as well as for your hydroponic system.

Setting Up Your Hydroponic System Correctly

Now you understand all the reasons that pH levels are important to your hydroponic system, and the plants you’re growing, it’s time to test your pH levels and get your hydroponic system running before introducing plants into the environment.

If you are still researching, the following will still apply because pH testing isn’t a one shot thing. In the beginning, you can be doing this on a daily basis until you understand how your system works. To test your pH levels, there are various ways you can do this.

By the use of litmus strips, or digital testers, you can quickly find whether you need to adjust levels up or down.

One thing to note here is that some of the better hydroponic nutrients come with a pH buffer. This takes away any sudden level change to your plants. While you still need to adjust, the extent of what you do will be minimized.

Litmus Strips

Litmus strips are one of the quickest and simplest ways to test the pH in your system. Although they are easy to keep on hand, you shouldn’t rely on them without another means of measuring in place. The way these works is the paper contains a dye, which is sensitive to any liquid it comes into contact with.

To test your system, take a sample of your water in a sterile container. Dip one of the strips into this wait until the color changes. Once there are no more changes, you compare this against a chart, which comes with the litmus pH testing kit.

You may find some of the colors can be hard to distinguish from each other, so trying to guess which one it is, isn’t the best way to be safe. Many plants may not bother with this little difference, yet this half a reading in either direction can affect plants that require a tight tolerance.

You can also find liquid testing kits, which work in the same way. With these, you add the dye to your sample, and then once the sample finishes changing color, you compare this against your chart.

Hydroponic pH Pens

The most reliable option works out the most expensive, however, this is not overly expensive, and it can last much longer than your litmus testing kits. On top of this, you will have a digital readout, so there is no way to make a mistake.

One of the common designs is the digital pH pen. Once you place the nib in your water sample, you get an exact reading, which is precise. One downside with these is that over time, the readings may fluctuate, this means your pH pen requires calibration. If you perform lots of testing, this can be a weekly exercise.

We have written a complete guide to testing the pH of your water, we highly recommend understanding the full process to stop your plants wilting.

Continual Water Treatment and pH Balancing

Now you see the equipment you need to use to test your nutrient solution; we will look at how the varying hydroponic systems can have varying pH levels. One of the more straightforward are NFT (Nutrient Film Techniques) as your solution is in direct contact with the plants root systems.

Media based systems can have readings that vary one way or the other. It is for this reason; you need to take two separate readings. The first needs to be taken from your nutrient reservoir, and the leachate, which is the chemical runoff.

This is necessary because you will have different readings before and after the rooting system. This may not vary too much if you have smaller plants, yet larger plans will mean the variance is much higher.

When adjusting your solution pH levels, the base adjustments in the reservoir need to be adjusted to the readings you obtain from the readings you come up with from the runoff solution. The reason this needs doing is that your plant roots will be facing the pH levels in the solution, which passes them, and not the solution in the reservoir.

Adjusting Your Hydroponic pH Levels

Your pH levels rise and fall for all manner of reasons. Luckily, we have seen how easy it is to fix some of these. We also saw that your nutrients would come with pH buffers when you purchase them from reputable suppliers.

These buffers are a great way to prevent spikes or drops which may shock your plants. Aside from this, these suppliers also offer chemicals that you can use to raise or lower your pH levels. One of the more frequently used comes from General Hydroponics. These have pH UP and pH down you can purchase. Because of the pH sensitivity, you do need to follow recommended doses and take separate readings, in case you need to adjust again.

The aim when making your adjustments is to make sure there is no nutrient lockout. This takes daily readings to be sure your pH level is going in the right direction

When you come to make your adjustments, there are only a few steps you need to take to make these adjustments. The main thing is to be observant of what your readings are.

  1. Take your first sample and then a reading Depending on the result you obtain, all you have to do is add between 1-2 ml of the pH Up or pH Down solution for each gallon of water you have in your reservoir.
  2. Once you add this, stir your solution with a clean implement and wait a minimum of 30-minutes so the solution can run around your system. At this point, you can take your next reading.
  3. You need to repeat these steps as required until you reach the required level. Never be tempted to add more of either chemical to reach the results faster. This will, shock your plants because you may swing too far in either direction.

When you add new nutrients, they will change your pH levels, which is why you will always need to do a new test once these have been added to the new reservoir. Other than that, it is recommended to run your tests more or less the same time each day. There are a number of natural approaches to tuning your pH if you have no pH Up or pH Down.

This is a very short-term solution and you should only use this if it is absolutely essential. Either white vinegar or citric acid may be used to reduce the pH, whereas baking soda is used to raise your pH levels. When doing this, you will need to know how much of a change there is for the amount you add.

Maintaining pH Level Recap

To summarize all the above, here is a quick recap of everything we have shown. Following these, you can maintain your pH levels and have plants that are continually thriving.

  • Check your levels daily until you get to know your system. When you see how things are running, you can reduce your testing to 2 or 3 times per week.
  • Even if you can’t afford the best testing kit there is, you should look for the best one you can afford. Litmus tests are handy to use, yet when you attempt to adjust your readings a few times, these are not as quick as pH pens.
  • If you spot your pH, levels fall between 5.8 – 6.5. You should not be tempted to make any adjustments. This reading is ideal for most plants that you may be growing.
  • Solutions which have a high pH need adjusting with pH Down.
  • Levels, which are low, need adjusting with pH UP.
  • Keep records of your testing and how much solution you add into your reservoir.

Overdosing with pH adjusters or nutrients is highly harmful to plants. On top of this, if you have a solution that drops in your reservoir, the pH change at the same time. Even topping up with water will have an effect, so be sure all your readings are when you have a full tank.

Growers who understand what their plants need, and how to adjust to keep them healthy will have some of the best crops when harvest arrives. Any grower who thinks this isn’t important may face a catastrophe.

How to Recycle Hydroponic Water: A Beginner’s Guide

How to Recycle Water

There are so many options to support a thriving garden and hydroponics is one of the most recent systems I’ve read about. I’ve read that recycling hydroponic water can help save me money.

How to recycle hydroponic water: a beginner’s guide: Recycling water is a relatively simple process but can cost quite a bit of money between the initial investment and maintenance cost. You can use one of three main systems to recycle hydroponic water. Here’s a look:

  • Pasteurization
  • Ozone Sterilization
  • UV Disinfection

If these systems sound as foreign to you as they do to me, I’m here to help. Take a look at a beginner’s guide on how to recycle hydroponic water.

The Importance of Cleaning Recycled Hydroponic Water

You’ll see many benefits from hydroponic growing but one thing you’ll quickly realize is that the system produces huge amounts of wastewater. Rather than just toss the wastewater (which is a bad idea anyway), many growers are starting to recycle their hydroponic water.

Recycling hydroponic water is a great idea. It cuts down on your water use and cost and helps prevent damage to the environment. That’s right, what’s good for your plants may not be good for the environment.

The nutrients that help your plants grown quicker than normal and produce more fruit can negatively affect the environment and groundwater that is turned into drinking water for humans.

Hydroponic solution is normally made up of at least a few of these nutrients:

  • Nitrogen
  • Phosphorous
  • Potassium
  • Calcium
  • Magnesium
  • Sulfur
  • Iron
  • Boron
  • Copper
  • Manganese
  • Zinc

(If you haven’t read our articles about DIY nutrient solutions or if nutrients can go bad check them out)

Certain studies have found high levels of nitrogen and phosphorous in hydroponic water that was dumped. Those two nutrients, along with sunlight and slow-moving water, are what create algae blooms.

Algae blooms have a number of negative effects on our environment. Here are the four main issues:

  • Algae blooms produce dangerous toxins that can sicken or even kill animals or people that come in contact with them
  • Algae blooms create dead zones in the water. A dead zone is an area with low oxygen levels (low oxygen levels can lead to root rot). Eventually all the animals in the “dead zone” die.
  • Consumers see higher treatment costs for drinking water affected by algae blooms
  • Algae blooms hurt industries that depend on clean water.

While I’m sure you’re concerned about the effects on the environment, the other appealing reason to recycle your hydroponic water is the cost savings to you by not using as much water.

Plants grown in hydroponics already use 80 to 90 percent less water than standard plants grown in soil because the solution passes over the plants’ roots many times before you have to get rid of it.

Before you start reusing and recycling your hydroponic water, it’s important to clean and sterilize the water. It can carry bacteria, viruses, and other diseases. If you put this back into your system, you could potentially infect and damage your plants.

As I mentioned before, there are three main systems used for sterilizing your hydroponic water:

  • Pasteurization
  • Ozonation
  • UV Disinfection

There are pros and cons to each system. Take a look at this table comparing the systems.

System Pros Cons
Pasteurization No need to pre-filter water, minimizes buildup of minerals in water Causes mineral buildup in pasteurization machine
Ozonation Most effective form to sterilize water, environmentally friendly, prevents disease Expensive, highly corrosive- can damage equipment
UV Disinfection Highly effective, chemical-free, cost-effective Doesn’t remove heavy metals, salts, or chlorine

Now, that you’ve taken a brief look at the pros and cons of each system, let’s dive in and take a deeper look to figure out which system might be best for you.


You might be familiar with the term pasteurization because it’s used in many of our everyday foods: milk, juices, egg whites, etc.

The process of pasteurization kills harmful, pathogenic bacteria. Removing the bacteria prevents diseases such as typhoid fever, tuberculosis, scarlet fever, polio, and dysentery.

Of course, these diseases aren’t an issue for your plants, but using pasteurization on your hydroponic water removes other bacteria that might harm your plants.

So, how does pasteurization work? Take a look at this process.

  1. The used water is run through a 50-70 micron filter reducing the pH to 4.5 (learn how to monitor your water pH levels)
  2. The adjusted solution is pumped to the first heat exchanger
  3. This heat exchanger preheats the water while recovering heat from the sterilized solution
  4. Sterilized solution leaves the first heat exchanger and is pumped into the second heat exchanger
  5. An external heat source heats the nutrient solution to a certain temperature, ideally at least 203 degrees Fahrenheit
  6. The nutrient solution is exposed to the high temp for at least 30 seconds
  7. The sterilized solution is returned to the first heat exchanger to cool

It sounds complicated but you don’t actually have to do much.

As I showed in the table above, using pasteurization to sterilize your water prevents excessive mineral build up in the water, but can lead to mineral build up in the machine. This can decrease how well your machine works.

Your best bet to find a pasteurization machine for recycling your hydroponic water is in a specialty garden store or catalog.


Ozonation uses ozone to sterilize the water. Ozone is just oxygen with three molecules. During ozonation, the water is infused with ozone. The gas ozone is created by ozone generators in your grow room.

There are two types of ozone generators: corona discharge and ultraviolet. They work by splitting oxygen molecules into individual oxygen atoms. The atoms then bind to oxygen molecules creating ozone.

Here are all the steps to complete ozonation.

  1. The water is filtered with a 50-70 micron filter.
  2. Check the pH level of the water to make sure it’s between 4.0 and 4.5. This gives you the best results.
  3. Your hydroponic water is pumped into the ozone generator.
  4. The amount of ozone and length of sterilization depends on the level of nutrients in your water.

The benefits of ozonation as shown above are that it’s very effective and environmentally friendly. The downside is that ozonation can be costly and it’s highly corrosive so you have to be careful when dealing with it.

UV Disinfection

One of the final methods of high tech sterilization is ultraviolet or UV disinfection. UV radiation is part of the electromagnetic spectrum.

There are three types of UV radiation and they’re defined by frequency and wavelength. The best type of UV radiation for disinfecting your hydroponic water is UV-C. This type has the shortest wavelength and the highest energy.

UV-C radiation very efficiently kills bacteria, fungi, and viruses. Based on various studies, it looks like 250 millijoules per cubic centimeter is the appropriate radiation dose to totally disinfect the water.

Here’s a look at how UV disinfection works.

  1. Pour the water into a disinfection unit.
  2. The hydroponic water passes through a radiation chamber.
  3. High pressure UV lamps contained in a quartz tube in the chamber disinfect the water.
  4. A computer controls the process. If the UV dose is too low, the process is blocked and the water is returned to a drain water tank.

UV disinfection is pretty cost-effective compared to pasteurization and ozonation. It’s also natural. The only downside is that it doesn’t neutralize organics, chemical contaminants, or inorganic compounds in the water. This means it doesn’t remove heavy metals, salts, or chlorine that may have built up in the water.

Whatever sterilization method you choose, it’s essential to recycling your hydroponic water. You have to kill any destructive microorganisms that may have grown during the previous cycle.

Other Possibilities for Recycling Hydroponic Water

If the recycling options we talked about above sound like they’re out of your financial abilities or too much of a time commitment right now, you can consider just using the water on your other plants.

It’s important, though, to check the levels of the nutrients in your hydroponic water to make sure they’re not too high. If they’re too high, don’t use the water on any plants that are directly in the ground because the nutrients could affect your local water table.

A good way to check the nutrient levels in your hydroponic water is to check the potential (pH) and electrical conductivity (EC) levels. If these are within a certain range, your hydroponic water should be safe.

A good pH level is between 5.5 and 6.5. An appropriate range for EC levels is 1.2 to 2.0. You can read our full guide to EC and why you should monitor it here.

Plants in one study even showed better growth using recycled hydroponic water than those without. Here a look at the plants that performed well:

  • Tomatoes
  • Red peppers
  • Cabbage
  • Melons
  • Cucumbers

There are a few other options for recycling your hydroponic water that you may hear talked about. While they have some effectiveness, they’re not recommended because none of them completely disinfect the water.

These are the other methods you might hear about:

  • Ultra-filtration
  • Hydrogen Peroxide
  • Iodine


Ultra-filtration is also known as membrane filtration. It includes the process of reverse osmosis. These types of filters have more porous membranes that allow solids, bacteria, and other large particles to be filtered out.

The main problem with this process is that the pores in the filter tend to clog making it an unreliable choice. The other problem is that the filters also remove fertilizer salts from the water, which are helpful for plant growth.

Hydrogen peroxide

Hydrogen peroxide works in much the same way as ozone does but it’s weaker. Because of this, it’s effective against fungi and viruses but not so much against bacteria.

If you recycle your hydroponic water but it’s not totally disinfected from the bacteria, you’re asking for trouble as soon as your plants touch the water again.

Levels of hydrogen peroxide that are too high can also damage your plant if they’re not neutralized before you return the nutrient solution to your plants.


You may be familiar with iodine because it’s used in drinking water to kill human viruses, but it doesn’t actually kill horticulture viruses. This means that it’s not effective for disinfecting your hydroponic water.

Recycling hydroponic water back into your other plants still ends up saving you money and might even give you more plant growth.

A Key to Successfully Recycling Hydroponic Water

You can set yourself up for success in recycling your hydroponic water right from the start. Keeping your nutrient solution levels under control is key to extending the life of your hydroponic water before you even need to recycle it.

The best way to keep the nutrient level under control is to make sure you’re only putting in clean water. This means when the water level dips, refresh it with totally clean water. If you don’t, trace elements in the water will eventually accumulate to toxic levels.

If you were thinking you have to dump your entire nutrient solution any time the level drops, it’s time to do a little research. You can actually refresh the nutrient solution with clean water until you’ve replaced half of your system’s water capacity.

For example, if you have your hydroponic system has a 20-gallon water capacity, you don’t need to empty all of the water until you’ve replaced 10 gallons. This means that keeping meticulous notes is super important so that you do know when it’s time to recycle your water.

Rain water, city water, and well water are all possible options for clean water to replace water that is used. It’s always still important to do a water analysis, especially on city water and well water, to ensure that all elements are within a reasonable level.

Cities sometimes have to “shock” water with large amounts of chlorine to get rid of some sort of biological contamination. These high levels of chlorine can harm your plants.

Well water sometimes has very high levels of bicarbonates. Phosphoric acid is used to lower these levels, but sometimes a byproduct of the treatments is calcium phosphate. This can clog drip lines and submersible pumps and affect your nutrient solution.

You’ll quickly learn a key to success in hydroponics is very routinely analyzing the mineral levels in the water.

What Exactly is Hydroponics?

If you’re looking to recycle hydroponic water, I’m assuming you’re already aware of the ways of hydroponics. If not, though, I can give you a brief explanation so you know what you’re getting into.

Hydroponics is a way of growing plants in a water-based solution rich in nutrients. This type of growing doesn’t use soil, but an inert medium instead. An inert medium is one that doesn’t have any nutrients. Here’s a look at some possibilities:

  • Perlite
  • Rockwool
  • Clay pellets
  • Peat moss
  • Vermiculite

Hydroponics works when the plant roots come in direct contact with the nutrient solution.

There are quite a few benefits to hydroponics. One of the main ones is that your plants grow quicker, up to 25-percent quicker. They’re also more productive, sometimes producing up to 30-percent more than plants grown only in soil.

The quicker growth and production happens because plants can access nutrients quicker and expend less energy. Because of this, they don’t have to grow a super big root system and can instead focus on growing quicker above the roots.

Along with the advantages of positive growth and production, hydroponic gardens do have some downsides. Here’s a look at some of them:

  • Initial cost
  • Time and commitment
  • Technical knowledge
  • Threat of power failure

Initial cost

You’ll spend some money upfront to get your hydroponic system up and going. You need containers, light, a pump, a timer, one of the growing mediums mentioned above, and nutrients.

Try to keep your initial investment under a few hundred dollars if you just have a small home garden. The good news is after your initial investment, your only costs are water and lighting.

Time and commitment

If you’re looking into hydroponics, you’re probably willing to invest some time in your garden. If not, hydroponics may not be the best choice for you.

You can’t just set up your hydroponic system and leave it. It requires monitoring the water level and the nutrients and adjusting the levels as needed. Unlike using soil, if the levels are off, the plants won’t just adjust to the changes, they’ll die.

You may eventually be able to automate your hydroponic system, but not initially. First, you need to get a feel for the needs of your plants.

Technical Knowledge

A hydroponic system isn’t just a simple pot with some soil. It requires putting the system together, figuring out which plants grow best with which nutrients, and making changes as needed. The elements are crucial to your garden’s success.

Threat of power failure

Finally, your whole system runs on electricity. This means if there is a power outage of any length, your system stops running. If the power doesn’t come back on within a couple hours, your plants will dry out and die.

A back up power source and a plan for if the power goes out helps minimize this disadvantage.

Despite the disadvantages, it’s worth giving hydroponics a shot. Eventually, you’ll save money and a great way to do that is by recycling your hydroponic water like we talked about above.

Hydroponics 101: How Hydroponics Works

A vast number of people have heard the term hydroponics; they may even know it’s growing plants without soil and in water. However, there is much more to it than shoving seedlings in water. If you were to do this, they would grow for a very short period, and then keel over and die.

The theory and practice in hydroponics is more in depth, and for new growers it can be overwhelming. We will look at the history of hydroponics, how it now works from its early beginnings, and then we will go through each part, and see how each works together, and influence each other.

The History of Hydroponics

The term hydroponics originates from “Hydro” which means water, and “Ponos” which means labor. It may sound like a modern technique, but in fact, it stems all the way back to “The Hanging Gardens of Babylon,” and the “Floating Gardens of China.”

Thousands of years ago, our ancestors were using the same techniques. While the principles are the same, the most significant differences are in systems construction materials, and how we now source nutrients.

It was in the past 100 years where there was a reference to the more up-to-date methods of hydroponics.

In the University of California, Berkeley, there was a man by the name of William Frederick Gericke. He began popularizing his ideas that we can grow plants without soil, and instead, they can use a nutrient rich solution.

At this time, it was unheard of, and his peers were quick to doubt and discard his claims. However, he was to prove all his critics wrong when he grew some very large tomato vines using his methods.

There was more research, they saw benefits for cultivation without soil, and Gericke came to coin the term, as we know it now, “Hydroponics.”

Hydroponic Benefits

Most growers know plants will grow faster and larger in hydroponics systems than in soil. There are however reasons they are able to do this. Here are the top four benefits of hydroponics over soil.

1# Pests and Infections

A hydroponic system will be away from any external influences. It will be a closed, water-driven system. Once this happens, there are no soil-borne pests around to hamper the growth of plants; likewise, the same applies to fungal infections and diseases, which can come from soil growth.

Soil growing is an ecosystem for all manner of microbes, insects, fungi and bacteria. There is a food chain occurring, and when you add plants into the equation, there are only two options. They can become a home for pests or fungi, or they can become a part of the food chain.

2# Chemical Usage

When growing in soil, there is a likelihood that herbicides, pesticides and all manner of chemicals are used to control animal and plant pests. Once you have a hydroponic system, you can eradicate the need for these. If soil growing is on a large scale, the grower or farmer’s health can suffer, in hydroponics, they won’t be under the same risk.

Natural means or fine screens such as mosquito nets can tend to most pests you may find in hydroponics. The only time you will be adding chemicals into the mix is when you are adding your nutrients.

One final area of benefit under chemicals is the reduced time you have for weeding. Because the growing area is segregated, there is no way for weeds to take hold and grow. This saves time and is one reason why there is no requirement for harmful herbicides.

3# No End of Growing Season

Soil needs time to recover once the harvest is over. In some instances, you can plant a second crop, but once that has come to harvest; you will be at the wrong time of year. This is where growers need to wait until the following spring before starting again.

Hydroponics on the other hand has no season end and has a quick turnaround once all your plants come to harvest. All you need to do is clean and sterilize your system, and re-fill with the next nutrient solution.

All through growing, you can test your nutrient solution and tailor everything to your plants.

4# Faster Growth

Faster growth is the benefit most growers know about. The reason for this is a culmination of the first three advantages. Because there are fewer pests and things your plants need to contend with, your tailoring of nutrients to deliver the optimum levels, makes sure your plants have the ideal growing conditions.

If you were to grow in soil, it takes more preparation to achieve optimum nutrient levels, because soil rarely has ideal growing conditions on its own.

How Hydroponic Systems Work

To understand how hydroponics works, it is good to know the fundamentals of each kind of system, and the benefits they bring. Here are six of the more common varieties of hydroponic system.

Flood and Drain (Ebb & Flow)

Plants sit inside growing pots full of growing medium, or they can sit in large Rockwool growing cubes. Spacing them apart, they then sit inside a flood tray. A timer runs your water pump at intervals to flood the tray to a set level. After a set period, the timer cuts off and your solution runs back into the tank.

Advantages of this system are its simplicity of build and maintenance. This actually mimics natural weather patterns with rain, but on a more frequent basis. As the tray is flooded, plants take up nutrients as they need them, and once the solution drains back, the roots gain oxygen from the atmosphere.

DWC (Deep Water Culture)

Growers suspend their plants above nutrient solutions in this type of system. This can be the lid of your tank, or it can be in a floating raft. To prevent your plants drowning, you use an air pump and air stone to oxygenate the solution.

If you have a raft system, there is less need for you to top the tank with fresh water, because the raft will lower along with the water reduction. If you use the lid of your tank, you do need to make sure water levels are high enough to reach your root systems.

Benefits of these systems are they are cheap to build, easy to run and maintain. Plants never go without water or nutrients. You can also use fewer nutrients in these systems than many others.


This is almost identical to a DWC system, albeit a little more advanced. In top-fed DWC systems, the water still reaches your plant roots, and you make use of an air pump and air stone. The difference being you now use a water pump, to deliver your solution via small tubes to the top of your plants root system. This runs back through the growing medium before passing back to the tank.

Benefits are the same as a deep-water culture system, and they receive highly oxygenated water to prevent drowning.

NFT (Nutrient Film Technique)

This system uses a water pump and gravity as the water delivery system. Your plants will sit in pots that sit inside sealed gutters or PVC tubes. These will be on a slight incline, and a continuous flow of nutrients runs along the channels where gravity pulls them back to the lowest point, which will be your tank.

The nutrients circulate, where just the root tips sit in the solution. Oxygen is absorbed by the upper parts of the plants root mass.

Benefits found in this system are plants will receive the ideal blend of nutrients, water and oxygen at all times. Once in operation, these levels are easier to maintain than in most other systems.

Drip Systems

Plants will feed from the continual stream from small tubes. These take water from the tank via a water pump. The amount of water is restricted to the amount that keeps your growing medium moist. All excess water passes back to the tank to recirculate.

Advantages of drip systems are the amount of water you can deliver. This makes it flexible for growing different plants in one system. You may have light feeders with a heavier feeding plant; however, you will need to monitor your nutrient levels carefully.


This system differs from all the others. Pumps spray a mist of oxygenated water and nutrients against rooting systems. Roots have lots of exposure to the air, so, they can absorb larger amounts of oxygen.

Advantages Aeroponics systems are the faster growing that you can achieve, as well as using less water in your system.

There are a couple of other hydroponic systems, which are variations of the above. There are also the passive versions, which run without using any mechanical methods of water delivery.

How Hydroponic Growing Media Works

There are a few different growing mediums, which are better suited to some hydroponic systems than others. However, in essence, the basic duty of all of them is to give support to your plants.

The second function is for them to hold water and oxygen. We know that roots require plenty of oxygen, and they can only absorb nutrients once they are in contact with water.

Because each growing medium differs, it can make the difference when choosing the correct one for your system. Early systems used sand as their growing medium, and while it offers a solid footing for plants, it lacks being able to deliver oxygen and water efficiently. The biggest problem being the size of the particles.

If you look at the opposite end and use gravel, this delivers plenty of oxygen, but it can’t retain water because this falls straight through the large gaps.

With this, here are the main four types of growing medium you will find.


The type you use will be horticultural grade perlite. It is one of the oldest growing mediums in use. Its benefits are it is readily available; it is light and delivers many benefits for any kind of gardening along with hydroponics.

Perlite comes with several benefits, which makes it an ideal growing medium:

Perlite absorbs water, oxygen and nutrients. It hangs onto these until they are ready for use by your plants. This makes it root friendly. Perlite is often an addition to soil because of its benefits, and even in hydroponics, you can mix it with coco coir to increase the water and air holding capacity.

Because perlite is light, it isn’t an ideal medium for flood and drain systems, it can be dislodged and end up flowing down return pipes to your tank. It is however a sterile material, and because of this, it tolerates changes in your nutrient mixes.

Perlite is capable of resisting fungi, which is perfect for a closed system like hydroponics. Anything, which can prevent fungi growth, is a good thing. In the right system, most crop varieties will benefit from perlite use.

Coco Coir

What was once a waste byproduct of the coconut industry turns out to be one of the best growing mediums you can find. Even after coconut harvesting and processing, it delivers natural plant hormones, and is another medium, which resists fungi.

The structure of coir is perfect for fine root hairs to spread and seek out their nutrient source. The coconut fibers are resistant to sun exposure, which they prove by bobbing across the ocean too far-off islands.

Now, with the benefits found for hydroponics, they compress the coir into briquettes. These require soaking before using for the first time. It may take a gallon of water as a minimum for one brick. Once you soak them, they will expand up to six times their original size. This shows coir is an ideal medium because it retains lots of water and oxygen.

Molded Sponges

These sponges are one of the better (miracle) mediums for use in hydroponics. They are a combination of polymer and compost. In most cases, growers use them in the germination stage where they help reduce transplant shock. They hold the ideal amount of air and water while guiding new roots down toward the moisture source.

This feature of molded sponges mimics the way roots seek out nutrients in soil. Using them, helps eliminate one of the bigger problems hydroponics growers face, and that is root systems, which grow in all directions.

Hydroton (Expanded Clay Pebbles)

These expanded clay pebbles are very popular because of their neutral pH. While they only possess moderate air and water retention properties, they are denser and heavier than perlite, so they are ideal in systems where this medium isn’t suitable, notably flood and drain.

These small clay pebbles are fit for re-use in different growing seasons and makes planting and harvesting far easier. Roots have little to cling so, so when you pull up your plants, the majority of the growing medium remains in your pots.

One of the biggest downsides is the possibility of these floating into your tank. Although heavier than perlite, it can take a while for them to be fully saturated. You also need to rinse them before use as there will be a lot of sediment that falls from them, and this can flow back to your tank and clog your water pumps.


This growing medium has been around for around two decades. They make these by melting rock, where they then spin it into thin fibers. These are then collected together and compressed into bricks of varying sizes. These are great for absorbing water, nutrients and air.

This is another material that is pH neutral, and free from any pathogens. It is ideal for re-use after cleaning/ sterilization, and can last for many years before it is no longer suitable.

The biggest problem with this material being it is the same as household insulation. Because of this, you do need to take caution on first use. Microscopic fibers and dust will escape on first use, and can lead to itching or allergic reactions.

Rockwool needs thoroughly washing to get rid of the threats before use, and while doing so, it is safer to wear rubber gloves and a facemask.

How Hydroponic Nutrients Work

One of the hardest things for new growers to understand is the nutrients used in hydroponics. Many opt for a one-pack solution that they use at all stages of a plants growth. However, these don’t deliver the optimum amounts of specific nutrients to get the best from plants.

Knowing how the nutrients work, goes a long way toward growers making the correct choice of nutrients. Additionally, many problems can be resolved when a grower knows the effects the nutrients have on their crops.

First is, nutrients are classed into two based on the relative concentrations in plant tissue.


These work on cellular levels, and you find them in larger amounts within plants. The primary focus is to aid photosynthesis, where plants use light to process the food from carbon dioxide and water. They take the chlorophyll (green leaf pigment) and convert carbon dioxide into oxygen.

Essential macronutrients are:

  • Nitrogen
  • Phosphorus
  • Potassium
  • Calcium
  • Magnesium, And Sulfur.


Nitrogen regulates plant growth and is the most crucial nutrient of all. Plants absorb, digest and convert them into amino acids. These are the core building blocks of proteins. Nitrogen is also one of the core components of chlorophyll.


Phosphorus is essential for flowering and root growth and is a primary component of DNA and RNA.


While you don’t find potassium in any parts of the plant, it does activate plant functions, so it is essential for overall plant health.


Calcium works in the same way as it does in humans. If there is a deficiency, it shows signs of stunted or distorted growth, and weakness. Calcium forms into calcium pectate, which is a pectin fiber, and the function in plants is to hold cell walls together, thus giving correct growth and strength.


Plants require chlorophyll so they can photosynthesize. The core property of magnesium is it is the primary structural molecule in chlorophyll production.


Plants need only small amounts of sulfur, but this doesn’t make it any less crucial to their health. The metabolic process in plants break down the sulfur into usable forms such as vitamins and others.

Other compounds sulfur produces are the ones, which produce the smells in garlic and onions (odoriferous).


There are seven micronutrients, and while these are required in much smaller quantities, they are as essential as macronutrients. The functions of these are to act as activators for further chemical reactions.

  • Iron
  • Manganese
  • Copper
  • Molybdenum
  • Zinc
  • Nickel
  • Boron, And Chlorine


The function of boron is to aid sugar transportation, amino acid synthesis and cell division.


The purpose of this micronutrient is to aid photosynthesis, help resist disease and for forming rigidity in the plants tissues and cells.


Copper is one of the key micronutrients that aids photosynthesis through enzyme production.


Iron is also an enzyme component that is vital for synthesizing chlorophyll and thus aiding in photosynthesis.


This is a chief activator for enzymes and chloroplast production.


Nitrogen metabolism occurs because of molybdenum. It is also a stabilizer of nitrogen some specific plant types (legumes).


Zinc is a chief component in many enzymes. It is crucial for the hormone balance in plants and the elongation of cells to regulate plant growth (auxin activity).

How Fertilizers Work

When growers gain more knowledge, they will understand how these nutrients work in their plants growth. There are several fertilizers and nutrient types you can purchase. This is why it is important to know about all the above compounds, especially the macronutrients.

You can purchase conventional fertilizers, or choose to go organic. There are a couple of key differences between these two.

Conventional Fertilizers

These are what you will find readymade, they comprise differing ratios of synthetic or manmade materials. The nutrients in these organic fertilizers are ready for absorption by plants, and deficiencies can be quickly resolved. They are inexpensive and readily available.

Organic Fertilizers

Organic fertilizers are made from broken down (natural) ingredients. These are generally byproducts from waste. The downsides of these is they are more expensive to purchase, and when applied to plants, the nutrients are available at a slower rate.

Liquid vs. Dry Fertilizers

Once you move on from this, you then have liquid vs. dry fertilizer. These can deliver the same results, but the conventional fertilizers in liquid form are much easier to use for newer growers. The downsides being higher cost and shorter shelf life.

Dry fertilizers do take some skill, as they require mixing in the correct ratios. You can tailor these to your plants effectively, and they do come with a lower purchase/ shipping price because they contain no water.

Multi-part or 1-part

New growers will more often go for liquid nutrients. These are available in 1-part or multi-part.

1-part contains all the nutrients needed for plant growth. The most significant downside to this being plants need different levels of nutrients at either stage of their growth. 1-part nutrients can’t be adapted, and you may lose some growth or yield as a result.

Multi-part nutrients come in two or three parts. Each of these caters for a different phase of plant growth. You start with the first part, and once your plants reach a specific point, you then change to the next bottle. If you have a three-part solution, the flowering phase will use the third bottle from your purchase.

It doesn’t matter which route you go, the crucial thing is to ensure plants receive the correct nutrients in the correct ratios. Each type of fertilizer or nutrient has their own benefits, but a crop of plants will not care which one you are using as long as they get their quota.

How Does Water Work in Hydroponic Systems?

Because hydroponics is based around water, this is the primary part of any system. You do need a means to grow your plants, and you will need nutrients, but without water, then nothing can happen.

What many growers don’t know in the beginning, is how water affects a system aside from being the carrier for nutrients and oxygen. Not all water is suitable straight off. You can have water from the faucet, and this will deliver very different results than pure water.

The reason being, faucet water changes depending on region, and, not only this, but it is not pure because of chemical treatments. This affects your water, and ultimately, it has an effect on your plants.

Reverse osmosis, or clean rainwater is ideal for a hydroponic system. These have no trace elements that can affect mineral or pH levels in your solutions.

There are a few things to understand how water works because it changes once you begin adding your nutrients, and when your plants begin absorbing these nutrients along with water.

How EC (Electrical Conductivity) Works

When you have pure water, it isn’t an efficient conductor of electricity. Once you add your nutrients (mineral salts), the EC levels rise. This means electricity can pass through the solution easier. The higher the salt concentration, the higher your EC.

With this, you can tell how strong your nutrient solution is. When growing, this will rise naturally because plants absorb water faster than they take up nutrients. It is here, you need to know how water works with EC.

Once your EC levels reach a certain point, it will affect the growth of your plants. If it is too low (less nutrient concentration), your plants may not receive all they need. If you have a reading which is too high (strong nutrient concentration), then your plants will be showing symptoms that are affecting their growth.

There is an optimum EC level for each type of plant. Regular testing with a digital EC meter is advisable.

Even though plants may suffer slightly from weaker concentrations, it is better to edge toward weaker rather than stronger. It is easier to adjust, the damage to plants is less, and easier to rectify.

How pH Works in Hydroponic Systems

The pH levels in your system are one of the key factors in your water working effectively. This is the measure of acid or alkaline in your system.

Along with your EC levels, the pH level will change when you add your nutrients. The key factor here is it will affect how easily your plants can absorb the nutrients from the water. It is these fluctuations in either direction, which causes nutrient lockout.

Once this happens, the key macronutrients are harder to absorb, yet the micronutrients become easier and in larger quantities, these become toxic to plants.

You can purchase a simple digital pH meter, which works in the same way as your EC meter. The ideal pH levels for plants is in between 5.5 and 6.5. It may be the case; you need to measure solutions daily until you understand how your system works.


Hydroponics works in many ways because there are countless variables at play. For many new growers, it can be hard to understand each part and how they go to affect the performance of a system. One thing to remember is it was possible for growers thousands of years ago to do the same thing using sand and gravel. Although it can be frustrating at times. There is no part of a hydroponic system, which causes problems; a grower can’t find a solution for. This leads them to a fruitful and successful system they are in complete control of.

How to Build a Wick System

Hydroponic wick systems are one of the easiest hydroponic systems a grower can make and operate. Because of their simplicity, they are the cheapest to set up. These are fantastic for growers who are new to hydroponics, or for veteran growers who have spare space and wish to make full use of the area.

A hydroponic wick system can comprise as few as five individual components; this even includes your plants. Although, you can expand on this a little if you so wish. These systems are super easy to build and use, but there are some things to know along the way.

Here, we will look at all you need to know about constructing and running a hydroponic wick system.

Basics of a Wick System

In the purest form, all you need to build a wick system is a reservoir, your pot and growing medium, some nutrient solution and some wicking material. This can be strips of old clothes, rope or anything else capable of absorbing moisture.

The way these systems work, is by capillary action this you see in everyday life.

Here are a couple of examples of this in action:

  • Clothes that draw sweat away from the body.
  • Paper towels soaking up spilled liquids.

Plants do exactly the same thing, when their roots absorb moisture through the growing medium.

Capillary action occurs, because by essence, water droplets are sticky, so when they enter thin tubes (or porous materials) they start clinging to the sides of the tubes. Once this happens, something called meniscus occurs. This merely means there is a curved surface on the top edge of the water droplet.

Water droplets cling together through an internal bond of its molecules. This creates surface tension. With the sticky force of the droplet and the walls of the capillary tube, the droplets move upward. However, there are limits of how far this can travel in reality.

When you build a wick system, capillary action goes into action. The wick sucks water and nutrients up from the reservoir to your plants, as they need it.

Pros and Cons of a Wick System

Like any hydroponic system, there are pros and cons to each. Here are the upside and downsides of this simple system.


  • A porous growing medium will increase oxygen absorption by your plants
  • A wick system is very easy to understand and to build
  • They are the cheapest to build and maintain
  • Wick systems can be made from anything and will fit in the smallest of places
  • Once running, they require very little maintenance or management


  • Although a wick system can produce great results, yields can be lower than other systems
  • Larger plants will require oxygenation of your nutrients
  • You will need to change your solution to keep nutrient levels constant
  • The likelihood of mold increases because the water is not circulating

One thing that links to the downsides, is plants, which are heavy feeders. These will take up more water, so your EC levels will rise. Not only this but also some large plants may take up water and nutrients faster than your wicks can deliver them to your growing medium.

These systems are more suited to lettuce or herb types of plants rather than tomatoes or peppers.

Components of a Hydroponic Wick System

Out of all the components in your wick system, the wick is crucial. The choice of material dictates how fast and how much liquid can travel through it to reach your growing medium.

Because there is a vast number of materials you can use, you can perform a simple test. If you place some food dye in water and then insert your material, you will be able to see how fast and how far it can travel.

This will give you an indication which material serves you the best. One other notable thing is to place two wicks for each planting area if you use larger buckets.

Items required

  • A container or bucket for your plant
  • A container or bucket for your nutrient tank
  • A suitable wicking growing medium. Coco coir, perlite, vermiculite are ideal choices for this system
  • Wicking rope or your chosen wicking material (about 2-3ft of 1-inch thick wicking material)
  • 3/4 inch drill bit
  • Electric drill
  • Air pump and air stones – optional

Wicks – when you have your wick, you need to wash them beforehand as this can improve their performance. Depending on your system size, you will possibly require 2 to 4 wicks. The less distance water needs to travel, the better the performance of the wick.

Reservoirs – these can be any size as long as they are big enough to cope with your plants. There is a limit how small, but there is no real upper limit of size. They will require topping up with water so the end of the wick never sits above the water level. The closer the water to the top of your tank the better your wick will perform. Like other hydroponic systems, no light should be able to enter your water tank.

Air pumps – you don’t need the inclusion of an air pump, although, there is nothing wrong with adding one. This will increase oxygen, and it will help prevent nutrients from sinking to the bottom of your tank.

Growing Medium – You will require a growing medium that is capable of holding moisture. It can take some trial and error to find the right combination of wick and medium that work well together. If you find your wick is very efficient in soaking up moisture. You may need to add some larger growing medium like perlite or gravel to your initial growing medium to prevent over watering. Sand, coco coir or vermiculite are ideal mediums to begin with. 

Building Your Own Hydroponic Wick System

After looking at the basics of a Wick system, you will see they are easy to build with very few components. With that, we will now go through the building instructions. This will be using a 3-gallon bucket, but you can use any size as long as you have a second container suitable for your reservoir.

Tip: Two buckets of the same size are often used. One sits inside the other and rests against the side of the first, or rests on a brick that you place in your water tank.

Step by Step

  1. Take your 3-gallon bucket and drill a 3/4 inch hole in the center of the bottom.
  2. Fill your reservoir with enough nutrient solution so it reaches to just below your growing bucket once it is in place. Reserve one jug of your solution for the final steps.
  3. Insert your wick through the hole and make sure it is long enough to reach the bottom of the reservoir. You will have around 1 foot inside your pot and 1 to 2 feet inside your reservoir.
  4. Unravel your wick inside your growing bucket and then fill with your growing medium up to 2/3rds full. (Wicks need to be close to the plants rooting system, and long enough to be covered in solution as levels drop).
  5. Insert your plant in the bucket and fill the top third of the pot with more growing medium or use Hydroton pebbles.
  6. You can place your growing bucket inside your reservoir. It is advisable to make sure no light can enter where your nutrients are, because this prevents algae growth.
  7. Gently top water around your plant with the solution from your jug. This prevents the growing medium from leeching moisture from your plant roots.

If you are using an air pump and air stones, all you need to do is make a small hole in the top edge of your reservoir and feed in the pipes (change clear for black tubing), this will add more oxygen to your water and aid in plant growth.

Maintaining Wick Systems for Optimal Performance

Wick systems require very little maintenance, but they do need some care an attention at some stages. A lot will depend on the size of your wick system to how much maintenance you do need to carry out. However, some of the principles are the same regardless of the size of system.

You may find plant growth slower than other systems. Nonetheless, there are a few things to help your plants along, like adding air stones.

These few pointers can help you get the best plant growth possible from this manual kind of Hydroponic system.

  • Use multiple wicks so plants receive optimal amounts of water and nutrients – this will depend on your bucket size. Larger than 3 gallon buckets as in our example can use two wicks.
  • Keep water levels as high as possible – the closer the water, the less distance it needs to travel.
  • After harvest, be sure to rinse your growing medium and rinse off any salt build up. These levels will increase as your water levels drop. Only add enough nutrients and top off with plain water.
  • You will need to measure EC & pH levels using your digital meters.


For some growers, they may think these types of systems are too simplistic and are unable to deliver the results they want. While these systems are simple in design and function, they are more than ideal for squeezing in small areas.

As for not delivering results, a Wick system is more than ideal for delivering great results for the right kinds of plants. This allows growers to free up space in a full system and use this system for plants that require less continual attention. On a last note, there is no other Hydroponic system that is more suited to new growers than these systems. They are the ideal training ground to learn all about hydroponics.

How to Clean a Hydroponic System: A Step-By-Step Guide

Cleaning Hydroponic Systems

Every grower knows what it means to keep their hydroponic grow room clean and tidy. Because we grow plants in sterile environments, any sign of bacteria or algae or pathogens can quickly ruin a crop of plants in a matter our hours or a few days.

While these growers keep their areas as clean as possible, there are the systems themselves which need tending to. It is at this stage that keeping clean isn’t enough, and a hydroponic system will need more than sanitizing.

Sterilization can make all the difference when you have finished one harvest and are preparing things for another.

Here, we will look at how important it is to keep growing areas clean and what the difference is between sanitizing a system and to sterilize one thoroughly. With this, we will look at the materials you need, the cleaning agents you require, and how you need to use them in safe effective ways. To finish we will go through the entire cleaning process.

We will also look at some does and don’ts, and anything else which may be relevant to cleaning your growing room.

Why Keeping Clean is Important

While the health of your plants is crucial, the one most significant reason for cleaning grow rooms is the health of everyone who will use the bounty of a successful harvest. Human health is the top reason for performing these regular cleanings.

Other reasons to keep clean and sterile, is growers who already are, or aiming to have hydroponic systems for commercial ventures.

There will be certifications and standards that need upholding.

Sanitization Vs. Sterilization: What’s the Difference

There is often confusion between the two, but sanitizing and sterilizing a grow room and system, are different in their approach and the end results.

Sanitization is the ongoing maintenance, and in the most basic form, it is seen as keeping things clean and tidy.

Spilled water, dead plant matter, air intake filters are all part of this regular maintenance, and they will have an overall effect on your system performance.

All these three areas are breeding grounds for bacteria, and if not cleaned up, they will quickly spread to your plants.

Once you look at sterilization of a system, it is more in depth, because this involves the cleaning of the physical system, along with all the other components of your growing area.

When performing sterilization, you rid the entire growing area of viruses, bacteria, fungi and microorganisms.

In the times you sterilize your system, you prevent any pathogens or forms of mildew from spreading.

Most times, sterilization needs to be performed after a harvest.

If you have a separate growing area where to move your plants while sterilizing, this is ideal. However, this for many is a luxury and not always possible.

There is a difference between the two, and growers should never think sterilization alone is sufficient.

In between these times, there is still a need for sanitization.

Both are required, and they will make use of different materials and processes.

Materials Required for Sanitization and Sterilization of Hydroponic Systems

When you are planning to clean your system, you will need a certain set of tools, and the cleaning agents to rid your system of microorganisms.

Tools Required

  • Sponges and green scrub pads
  • Stiff scrubbing brushes
  • Bottle brushes
  • Long handled brush
  • Mop and bucket
  • Rubber gloves and goggles
  • Clippers and scissors – removing dead plant matter that has not fallen
  • Wet/ dry vacuum – optional
  • Clean rags
  • Compressed air cans – great for cleaning ventilation grills on ballasts and control units
  • Spare buckets
  • Garden hose with female hose adapter

Cleaning Agents Required

  • Hydrogen Peroxide – food grade
  • Bleach – unscented
  • Isopropyl Alcohol
  • Glass cleaner – you can use this, but we prefer either alcohol or vinegar
  • Vinegar – optional. Vinegar makes a great organic sanitization cleaning agent

Dos and Don’ts of Sanitization and Sterilization in Hydroponic Systems

Even following all the steps for cleaning your hydroponic system, there are some dos and don’ts you need to know of. These can not only harm your plants but also harm you if you don’t take the right precautions.

Here are a few things you need to do and don’t do when sterilizing your system.

Do Read the Label

While the cleaning agents may appear harmless to a certain degree, this isn’t the case. You will find health and safety information on the chemicals in use. Be sure you read the labels and fully understand the risks involved for you, and for your plants.

Do Make Sure Safety is Top of Your List

No one enjoys wearing goggles and rubber gloves, but when using these chemicals, it only requires a splash into the eye to cause irritation at best. If you are using a chemical that is too strong, this can kill your plants straight away, and it can lead to injury.

Rubber gloves are crucial as they can prevent chemical burns when using high concentrations of these cleaning compounds.

Do Know Your Solutions

Even after reading bottle labels and wearing the right protective gear. You need understand the chemicals you use.

A prime example being hydrogen peroxide.

The food grade variety has a stronger concentration than bottles you can purchase in the supermarket.

This variety only lowers its concentration when you dilute it, and until then, it is dangerous.

Don’t Mix Chemicals

It may not be intentional, but you need to make sure, you never mix any chemicals. The main one you need to take caution with is bleach. This doesn’t take well to being mixed with any other liquid. Something as simple as vinegar when mixed with bleach can create chlorine gas; this can cause many symptoms that can be harmful.

Don’t Use Concentrated Solutions

If you add anything to your tank while you have plants in your system, you should never add anything with in strong concentrations. Although you can use hydrogen peroxide in a running system, you must make sure you follow the recommended levels. Vinegar might appear harmless, but even this can damage to your system. Bleach should never be added to a running system that has plants growing.

Food Grade Hydrogen Peroxide

Although you can purchase hydrogen peroxide in different strengths, you need to make sure this is ‘Food Grade.’ This means, they classify it as safe for humans, and contains none of the compounds such as acetanilide which prevent the liquid breaking down.

However, you do need to take caution when using full strength 35% hydrogen peroxide.

It will burn when it is exposed to the skin. Using rubber gloves is still a recommendation when handling any quantity of hydrogen peroxide.

It is for this reason; you need to dilute this down to a 3% solution before use. For cleaning, you mix one part 35% hydrogen peroxide with eleven parts of clean water. This will be safe on all areas you wipe down, and safe for your plants.

Areas to be Cleaned in Hydroponic Systems

When you come to clean your system and grow room, it is safer to do so in between harvests. This means there is no risk of your plants becoming stressed, or any of your cleaning chemicals causing problems. It also gives you a chance to go through each part of your system one by one.

The extent of cleaning will vary depending on the size of your growing room, and the types of system you have. Although these will differ, the cleaning methods will be the same.

One tip to remember is that it is much easier to begin at the top and work your way down. There is little point in cleaning your system then disturbing dust that will fall onto your clean surfaces.

Remove Plants

If you have plants in your growing area, you should move away these from the areas you are cleaning. If you do this, you need to make sure you are using the same growing medium, the nutrient levels are the same and your solution has the same pH level.

It will introduce a lower amount of plant stress when you replicate their growing conditions. You will see it is far easier to do this cleaning in between harvesting.

Walls and Work Surfaces

You should scrub all walls and work surfaces. You can use water and hydrogen peroxide or vinegar for this. It is worth wiping down a first time to remove dirt before wiping down a second time to disinfect these areas.


Your lighting in most cases will be the highest element in your system.

You may not think it necessary to clean these, however, they are areas bacteria can grow, and are prime areas for collecting dust.

In the extreme case, you will have ballast, reflectors, reflector glass and the bulbs themselves. All these components will benefit from a wipe down with a damp cloth. This will remove any settled dust.

When you come to sterilize, using glass cleaner on the glass can leave a residue. It is far more beneficial to give all your lighting components a wipe down with Isopropyl alcohol to sterilize them thoroughly. The bulbs or tubes should be removed and wiped down in the same way. Although you can use vinegar, alcohol evaporates faster and doesn’t leave a residue or streaking.

Electrical Areas

Regularly, you should clean the areas around electrical units either using an air compressor, or using the cans of compressed air they use for cleaning computers.

Equipment that benefits from regular blasting of air is your lighting ballast, fans, lighting timers, heaters, air conditioning units and dehumidifiers.

All this equipment has hard to reach areas that a damp cloth can’t reach. This does more than clean your equipment; it will improve their efficiency and prolong their effective lifespan.

Air Intake Filters

Although many hydroponic air intake systems will bring in fresh air, this doesn’t mean it will be directly from the exterior of where your grow room is installed. However, no matter where your air intake comes from, the filters will need to be cleaned. These need to be cleaned and washed at least once per month, this removes any dust and bugs as well as improving the efficiency of your intake system.

It is worth changing this on a regular basis to make sure you have the chance of clean air entering your grow room. You can use nylon stockings for intake filters. You can stretch these across openings, and they will provide a cheap, easy and disposable intake filter that you can change weekly.

Full System Cleaning and Sterilization

While all your work areas will make your grow room a much cleaner and healthier environment. You need to pay careful attention to the system itself. It is here which has direct contact with your plants, so making sure this is as sterile as possible is vital.

For cleaning your system, you need to remove your pots and growing medium. This will have separate attention. If using Hydroton pebbles, make sure these remain wet and don’t dry out.

Step #1 Draining Your System

The first step in cleaning a system will be the draining the current solution from your tank. While there are some systems that don’t use pumps, for the example, we will use a recirculating system. You can drain your system in two ways if your tank has a drain valve. If you are only using a pump, then you will only follow the pump method.

Return Pump Method: Turn off all electric to your system and take the pump from your tank. You will need to remove you’re the outlet pipe and connect the female connector to your pump. When this is connected, you can feed your hose to the desired drain point. When ready, you can turn on your pump and pump the water from your tank.

Once the water reaches the level of your pump, you need to make sure it doesn’t run dry. This will cause wear and damage. You need to turn off your pump.

Drain Valve Method: You follow the same principle as the pump method, but you use the drain valve to let the water run from your tank naturally. Your drain area in this method does need to be lower than your tank.

If you have a non-circulating system and your drain point is higher, then there is no other way to empty your tank than using your empty buckets.

Using the above methods will leave around one inch of water in the bottom of your tank. This needs removing by using a sponge and squeezing into a bucket unless you have a wet and dry vacuum.

Step #2

This stage is crucial after each harvest in case there are any bacteria, algae or pathogens lurking around your system. You can use one of two chemicals at this stage, although if using bleach, it requires extra care.

All chemical residues need removing before re-starting your system; this will require sufficient rinsing of all components of your system.

The ratio of sterilizing chemicals are:

  • Food Grade Hydrogen Peroxide: 35% concentration should be mixed 3mls per each gallon of water
  • Unscented Bleach: 1:100 ratio mixed with water. (1.3 oz. bleach to 1 gallon)

System Cleaning

  1. Drain your system by either of the two methods mentioned above.
  2. Remove any Air Stones: One recommendation is to replace your air stones each time you sterilize your system. This may not be workable for small system growers.
  3. Check all areas of your system and remove any debris, broken off roots or signs of algae growth.
  4. Use the sterilizing solution to wipe down your air hoses, tank lids, and other external areas with green scrub pads or clean cloths.
  5. It is advisable to change your 3/4 inch water hose. In most systems, this will be short so there are no significant cost implications.
  6. Fill your system with regular water and your choice of sterilizing solution (Hydrogen peroxide or bleach).
  7. Fill to just over your regular water level, as this will cover the line where algae growth can occur build up.
  8. Let your system run and circulate for between 4-6 hours.
  9. Scrub as many parts of your system as you can reach with your green scrub pads. This includes channels (PVC pipes), flood trays and buckets if using those kinds of system.
  10. All joints or hard to reach areas need scrubbing with a bottlebrush.

Note: Because it may be possible for bacteria growth during your growing phase, they recommend stripping down parts where you can’t see, and use bottlebrushes to reach inside as far as possible.

  1. Rinse out your system with fresh water. You will see lots of residue being washed around the system. All this should end back in your tank once you have scrubbed all the areas you can, as you flush your system, you must drain your system to prevent this debris re-circulating.
  2. If you are using bleach as your sterilization solution, you need to triple flush your system to get rid of any residue that may cling to the sides of your system.
  3. Drain your system of all water.
  4. One your system is free from any water; wipe all parts with a clean towel.
  5. To assist drying, use fans and turn on your HID lights if you have these as it can help with sterilization. Ridding the system of excess water at this point will stop any bacteria hanging around in standing water droplets.

Sterilizing System Components

Once you have cleaned your system with the above methods, you will need to turn your attention to other system components. This will be your pumps, pots and growing medium. We recommend Hydrogen Peroxide to clean your system, because of its effectiveness and not needing to rinse as many times.

For smaller components, you can make a bleach bath. This will be a 1:1 mixture of unscented bleach and water. Once you have this, you can soak your pumps, Hydroton pebbles and net pots. If you decide not to discard your air stones, you can soak these in your bleach bath.

Like your system, you will need to triple wash these items before introducing them back into your system. The difference being, you will be using nowhere near as much water.

Cleaning Excessive Salts from Hydroponic Systems

Mineral salt build up is another key area that requires cleaning. Nutrients not taken up by your plants build up around areas where water levels stop and evaporates. A good example being a flood and drain system. Pots and growing medium are places where these salts build up.

The Problem with Salt Buildup

These salt buildups will cause problems for your plants, if you top of your tank, you will add more nutrients, this adds to the salts already in the system, and you quickly find your plants are getting nutrient burn. This can be hard for new growers to rectify, as there are many symptoms that can lead them in the wrong direction.

While you are sterilizing your grow room, this is the ideal time to rid your system of all these salts before you plant your next crops. This will mean you have a clear route for your new nutrients mixes and there won’t be any miscalculation because of the mineral salts still in your system.

Dealing with Salt Buildup

We need to remove as much of these salts as is possible from the rooting medium. We do this by leaching or flushing the system. To do this, there is a large amount of water allowed to flow through the system in the shortest time.

This action dissolves the salts and drags them away from the areas where they have settled. In different growing mediums, the amount of salts that accumulate will vary. Hydroton pebbles and perlite retain less water than coco coir or Rockwool, so these two will require less water to flush out these salts.

During a growing season, it is hard to determine when you need to flush your system. However, experienced growers recommend flushing once per month to be on the safe side. This is more the case with heavy feeding plants because they will have more nutrients being drawn to their rooting systems.

This regular flushing helps prevent any problems, but it can make it harder to maintain correct nutrient levels with no adjustment.

Making Sure Salts are Removed

One of the best times to remove these salts can be during your sanitization phase. Your pots and growing medium can be flushed separately in your bleach bath, as it will require triple flushing. Before cleaning your growing medium, you do need to make sure there are no root remains remaining inside, as this helps bacteria form.

One of the best ways to tell these salts are being removed from your system is to use an EC (Electric conductivity)/ ppm meter.

Check your systems TDS levels before flushing, or rinsing your system, and then check after you have run it for a period. You should see the ppm of the TDS has risen. This means the salts have dissolved again and are back in your water.

During this flushing or leaching (either with or without plants), check the water line where water evaporates. Flood trays and up the sides of pots will have visible signs in the form of white lines where salts are. All these need cleaning so they can return into your water.

You can then finish your rinsing and tank draining. Once your system is dry, there should be no traces of this salt buildup.

Even if you perform this action during a growing phase, your plants can show positive signs of growth after a couple of days. You can then return to your regular schedule of fertilization.

When you perform this flushing as part of your system sanitation, it will be much easier to get the correct nutrient/ pH levels. There will be no traces of salt interfering with your readings.

The Ultimate Grow Room Sanitation

You should follow all the previous steps, but, there is one way a grower can ensure their grow room is sterile. To do this, you can use an Ozone Generator.

These can help prevent mold, predators, aid in sterilization and can disinfect a grow room in one go.

These generators are now inexpensive, so they can be a viable option. However, there is some caution required in their use. When using Ozone generators in confined areas, humans or pets shouldn’t remain in the vicinity. You should use a timer so you never enter a room where a large amount of ozone is present. If entering a grow room where an ozone generator is running, you need to hold your breath to prevent any ill effects.

These generators may sound like overkill, but for growers which have a grow room which may be hard to keep sterile, they make this straightforward.


Both sanitization and grow room sterilization are some of the most preventative measures and grower can take into having a successful grow room.

The chances of insects, viruses and pathogens passing around your system is reduced.

While there is, plenty of effort in carrying this out, it is one of the very few things that cost nothing but delivers high returns.

Not only will your plants enjoy all this attention, but you may have spent a considerable amount of money on lighting and other equipment. This will remain clean, will run efficiently and last longer.

You will protect your investment and have an increase in your systems performance. The contribution of your time will be rewarded many times over.

How to Build a NFT System

With the number of different hydroponic systems available for growers to purchase or build, there isn’t one that looks more elaborate or impressive as an NFT (Nutrient Film Technique) system. While it seems complicated to set up, in practice it is straightforward, and it is very flexible and modular so it can be scaled up without much extra effort.

While being easy to build and maintain, there are still factors that will determine the success or failure of the system.

Here we will cover all you need to know and how to go about building this kind of system, plus any quirks there are once you’re up and running.

How an NFT System Works

Simply put, you’ll have your channels where the nutrients will run down in a thin film along the bottom of the channel. These channels will be on a slight incline, so gravity pulls the nutrients along, and the water pumps only purpose is to pump the solution to the highest point. From here, it flows naturally to return back to the reservoir with no further assistance.

When plants have their roots bathing in this film, they are still exposed to the air, so oxygen intake is maximized, while they can absorb as much or as little of the nutrients and water as they require.

For this system, it is effortless to grow leafy green plants that have relatively short growth times. Various types of lettuce, spinach, and broccoli are ideal, as are some herb varieties. For larger plant types, these systems are not suitable because of their weight, and also the mass of roots they will produce.

NFT Trays, Gutters or Tubes

Before going too far, it is worth noting that many growers use PVC tubes for this kind of system. While these still work and appear to be the best, they are in fact not the best means of creating a channel.

The more ideal thing to use is gutters or trays which have a flat bottom. The reason for this being the more substantial surface will create a larger area in which the plant’s roots can spread over. This allows them to feed on a much larger area, and hence, better growth.

Growers who use tubes or channels that come with ribbed bottoms are using materials which aren’t ideal. These create pooling, so the surface area is reduced as is the air-to-nutrient film ratio. While plants will still grow, and grow very well, they may have reduced yields or take longer to mature.

Pros and Cons of an NFT System

It doesn’t matter which type of hydroponic system a grower uses, there will be pros and cons of each. NFT is no different, and there are things to consider. Luckily, the pros can outweigh the cons, so this is a good thing.

NFT Pros

  • Low water and nutrient usage
  • More economical use of growing media
  • Highly modular and can scale easily
  • Minimal groundwater contamination due to recirculation
  • Easy setup and to maintain
  • Easy access to check root condition
  • A consistent water flow helps prevent salt buildup

NFT Cons

  • A dead pump can cause plants to die quickly
  • Not suitable for plants with larger tap-root systems
  • Not ideal for plants that require support

Building a NFT System

Here we will go through all the materials needed, and how you can construct an all in one NFT system.

Materials Required

  • 8 x 8 ft. 2×4 pieces of lumber
  • 3 x Sawhorse brackets
  • 8 x 10 ft. X 3 in. PVC pipes
  • 10 x 3 in. PVC elbows – long sweep 
  • 1 x 3 in. PVC elbow – short sweep
  • 1 x 3 in. PVC pipe end cap
  • 1 x 70-gallon reservoir – with cover (can be black or white. No light should enter)
  • 6 ft. 1/4 in. Black Tubing
  • 1 x Submersible water pump
  • 1 x Submersible Pump filter bag
  • 1 x air pump – optional for maximum nutrient aeration
  • 18 x metal plant hangers (can use galvanized 3/4 inch hanger strap)
  • 36 x screws for plant hangers/ hanger strap
  • 1 large pack of 2 inch Net Pots
  • 1 x electric drill
  • 1 x 1/4 inch drill bit
  • 1 x 1.5-inch self-feed or hole saw drill bit. Don’t cut a 2-inch hole or your net pots may fall in.  

Assembly Instructions for an NFT System

While a lot can depend on your growing area, and how you can configure your NFT system. This system allows plants to grow around every part of the system if space allows. This means you will need access to both sides and both ends of the structure.

Making the Frame

  1. Connect the 2×4 lumber into the sawhorse brackets. This will give you 3 sets.
  2. Depending on where your growing area is, the feet can be buried for extra support
  3. Space the A-frames so one of the 2×4’s can sit across the top in the sawhorse bracket. Around 3.5 ft. in between the center A-frame and the outer ones are ideal.
  4. Brace the A-frames apart with some of the remaining 2×4 lumber.
  5. Make sure your three A-frames are sturdy before you add your tubing.

Preparing the PVC Tubing

  1. Before drilling holes and connecting the pipes, you need to cut the end pipes to length.
  2. At this point connect your plant hangers (Plant hangers are easier to use) to the legs on either side. When you measure, you need to allow for no more than a 2% gradient on each side of your planter frame.
  3. Place 6 of your 10 ft. tubes to the plant hangers and add the long sweep elbows. You can then cut the shorter lengths to connect these together. Mark on your pipes where the elbows fit.
  4. Your tubing should run around the A-frame from the top of one side to the bottom of the other (where your reservoir will sit).
  5. Once you have dry assembled your NFT system, you are ready to drill your holes.
  6. Allowing for where the elbows meet the long tubes. Mark and drill holes 6 inches apart. These should also be marked and drilled in the shorter end tubes. A system of this size should accommodate around 120 holes.
  7. In the end, cap, drill a quarter inch hole for the black tubing to insert
  8. When you have all your holes cut, re-assemble your piping, so all the holes face upward. Although there should be a good seal, they may leak so using some PVC cement, fasten all your tubes, elbows and the end cap together.
  9. Place the short sweep elbow pointing downward as the return back to the reservoir.

Preparing the NFT Reservoir

The reservoir should sit below the lowest point of the end pipe. When you connect the last elbow, this should pass through the lid of the tank, so the nutrients are not exposed to light, and the tank is also kept in the dark to prevent any algae build up. You can use any remaining piece of the tube to feed this from the pipe into the tank.

When you do this, allow for some space as the falling solution will help create oxygen in the water.

As the system recirculates, you should place your submersible water pump inside the filter bag. This can reduce the chance of any debris from clogging the pump. From the pump, you need to connect one end of your black tubing, this then goes up to the hole in the end cap and feeds inside.

For additional aeration, you can also make use of an air pump and air stones. This will help the uptake of oxygen by your plants.

At this point, you are ready to fill your tank and run water through the system.

Unlike other systems that have their pump controlled by a timer, this one runs 24/7, so there is always a supply of water and nutrients to the root systems.

NFT System Things to Consider

When you build this system, there are a couple of things to consider. These are just small things which can make your system operate more efficiently and help deliver the optimum conditions for your plants.

With this and many other systems, growers use round PVC, this is easier to find and to work with. In these systems, the solution can’t cover the root tips evenly. Flow rate and the slope of the tubes can lead to problems if they are not ideal.

If you can find flat based gutters with a solid cover, this is ideal, or any square PVC tube. Systems that use this are more often made from square tubing which is purpose-built for this. While you may think there are problems with the elbows, you can still use round pipes, but you will lose the chance to grow plants at this point.

The tubes on the system above are 10 feet in length, which is the longest you should go before you can encounter problems. Once you run the system, the plants at the very beginning of the tube run will receive the most nutrients, and the plants closer to the reservoir will receive the least.

Longer tubing might appear a good idea, but it can become detrimental to plant growth. Keep an eye on all the plant’s growth to make sure they are growing evenly.

When transplanting your seedlings, you can use a small amount of growing medium to help support the growing plants. Most often, expanded clay pebbles are used as they are inert and won’t affect pH levels of your solution. They are also very light and won’t place any excess weight on your tube supports.

If you decide to use an air pump with air stones, the larger the air stone, the better. This isn’t necessary, but the addition of these can help keep water agitated and will help your nutrient solution to last a little longer.

Like any hydroponic reservoir, you do need to make sure there is no light entering your tank, but one area many growers forget are the holes in their pipes. If there are no plants inside these holes, light can enter, and algae growth can occur. You can prevent this by covering the holes with a short of PVC tube that has been split. This makes an ideal snap-over cover.

While the system above uses a 70-gallon tank, this doesn’t mean you can’t go larger. If you have the opportunity, a larger tank can help buffer your solution and to maintain temperature levels.

Prepare Seedlings for Transplanting to an NFT System

When you are preparing your seeds, these will more often be started in starter cubes. These cubes can be made from different materials such as Rockwool or Coco Coir which are the most commonly used. Anything that can break away like peat moss can run down the channel and lead to a buildup in the tank and cause your water pump to clog.

When you come to ready your cubes, you will soak these thoroughly, this saturates them as well as washing out any excess salts that may have accumulated.

Because of poor germination or wastage, you should allow for this and plant around an extra 10% more. At this part of the germination phase, you shouldn’t be using any nutrients. Once they begin showing root growth, you need to keep the cubes moist but not over saturated.

Once the roots are protruding from the bottom of the cube, you can then transplant these into your net pots and your NFT channels. This will be around the ten days to 2-week period, although this will depend on your growing environment.

Choosing the Right NFT Water Pump

Out of all the areas which are crucial in an NFT system, it is that of your nutrient flow. With this, you do need to find the ideal sized submersible water pump.

To do this, we need to know the maximum head height the pump can work too. This is the height at which your pump can deliver the solution. As an example, if a pump has a head height of six feet, it can pump comfortably to a height of six feet in a vertical direction. If your inlet pipe is higher than this, then your pump can’t sufficiently deliver water. The reason for this is the weight of the liquid is greater than the force from the pump.

To calculate the size of pump required, you need to measure from the top of your reservoir to the highest point of your NFT system. Once you have this, you should add a further 20% as a buffer. With this, you will be sure your pump can comfortably deliver water to this height.

When looking for pumps, you need to remember, NFT systems don’t need high volumes of water. Because of this, you should choose a pump which is closest to your measurements without being under.

One other thing to remember is, GPH (Gallons per hour) and head height are not the same, but generally, as one increases, so does the other. What we need to look for is the lowest GPH pump, but one that meets the head height.

When you have this, you can think about moderating your flow, too much and you won’t be able to create the film inside the tubes.

This flow variation can be made if you have an inline tap where you can adjust the flow, but an easier way is to use a submersible water pump that comes with a variable flow rate. These are ideal for this kind of system as you can really fine-tune your flow to meet the needs of your system. They are also easy to adjust without the need for additional plumbing in your inlet tubes.

One final area where these pumps prove their worth is that as your plants grow, the flow of your solution may need increasing. You can find this by checking the last plants in the stream, if these begin showing signs of nutrient deficiency, then you merely increase the flow rate.


As long as you follow the essential elements of an NFT system, these are very easy to run and maintain. All the same consideration for cleaning and balancing of pH levels are still there, but they can be more stable once it is running.

While the above system is of a specific design, you can very easily modify this to build a system which fits into your growing area. Many growers have this kind of system flat against a wall rather than spiraling around a frame. Others have these set out in rows which are all level, and the solution is pumped into each channel individually.

Designs are varied, and will only be dictated by the size of the grow room and if you are using grow lights.

Whatever design you use, you will very quickly find that these systems produce great results for the types of plants they are intended for. Building them takes little effort, and once seedlings are transplanted, you can look forward to the highest of yields.

How to Build an Ebb and Flow Hydroponic System

When new growers begin their journey, they often look for a system that is easy to construct, easy to maintain while still delivering high yields. While the DWC culture system can be the simplest form of the system, there is another that is a little more hands-on, but it can deliver much higher yields.

This system is the Ebb and Flow system, and often called a ‘Flood and Drain’ system. There are many variations of this you can build, but we will concentrate on the main one with a quick mention of another type that is very easy for any grower to set up.

What is Ebb and Flow?

To simplify the process, this kind of system will involve the flooding and draining of water and nutrients into your growing media. This happens periodically and is taken care of by an electronic timer.

Altogether, two phases make up a full cycle. The flooding phase is when water and nutrients flow into the growing areas. This happens via a submersible water pump. This water level will be high enough to cover the roots of your plants.

Once this has been held in the growing area for a period, the nutrient mix will then be allowed to drain back into your reservoir.

To make sure that water levels don’t keep climbing, and not only swamp your plants, but overspill, the sides of your grow bed, you will have an overflow pipe, that allows excess water to return to the reservoir, as the water is being pumped into the grow bed.

One thing to note with this system is it is very adaptable to your growing space. The flood bed can be any size as long as it is suitable for holding your pots and plants while allowing them plenty of space in between. One other factor for the size will be your grow lights, these need to be sufficient to cover all of the grow bed.

Parts and Materials Required

Before looking at the parts required, it should be mentioned about the flood trays. While these come in different sizes, there is the depth you need to consider. As they flood, the water level needs to rise enough to flood over the roots of your plants, it also requires a couple of inches past this to make sure there is no overspill.

When purchasing, be sure to base your pot sizes on the depth of your flood table. If they are too tall, and the roots of the plants are not toward the bottom of the pot, they won’t be able to take up sufficient amounts of water and nutrients.

  • 1 x flood tray of a suitable size – black is the best color.
  • 1 x submersible water pump
  • 1 x air pump – optional, you don’t need this, but more oxygen is always a good thing.
  • 1 x digital or analog timer which covers 24-hours
  • 20ft x 1/2 Black tubing – this is way more than you need, but probably the least you can purchase.
  • Overflow and inlet fittings – Many growers make their own, but these Ebb & Flow Fitting Kits are super cheap and can make things far more comfortable to work with.
  • 1 x reservoir tank – opaque to deter algae growth

When it comes to sizing your water reservoir you need to know the following:

The height you will be flooding the bed too. This will be the tray height (H) x Width (W) x Length (L). For any conversion, use inches rather than feet.

When you have your final number, all you need to do is multiply this by 0.0043, and this will give you a figure in gallons the tank will need to hold.

To put this formula into practice, here is a real-world example.

Flood tray is 36 inches x 72 inches. You will flood the tray to four inches, and the plants will be growing in 6 inches squared Rockwool cubes or the equivalent size in pots.

Reservoir size (gal) = (36 inches x 72 inches x 4 inches) x 0.0043. This will give you a result of tank size that can hold a minimum of 45 gallons of water.

Note: Depending on the growing medium used, you may need to flood the tank higher. Most of the fitting kits come with an extension to easily allow for this. Also, any flood table over 4ft square will require 3/4 inch fittings. This needs to match your tubing, and also the connector on your water pump.

Assembling a Flood and Drain System

One of the most challenging parts of constructing a flood and drain system is making sure you have a suitable structure to hold your flood tray. Some growers use pond liner and build their own beds, but for new growers, an old table or something similar will suffice.

This should allow the flood table to sit above your nutrient tank. Once you have your support, you can follow these steps to construct the system.

  1. In the flood tray, drill two 35mm holes in the lowest part of the tray. These should be a few inches apart from each other. They should also be to one end of the tray as they will need to pass the edge of your support.
  2. Screw both fittings into the flood tray. The rubber seal should be on the inside of your flood tray while the tube fitting end should be sticking from the underside.
  3. Insert two or three of the Ebb and Flow extensions into one of the pieces you have just fastened to the bottom of your tray.
  4. Place one of the screen fittings to the top of this. You have now built your tray overflow. (You may need to adjust depending on pot size)
  5. Place one screen fitting onto the remaining piece that sits in the bottom of the flood tray. This will be your water inlet which is fed from your submersible pump.
  6. Place the flood tray, so the fittings hang above the hydroponic reservoir.
  7. You will need to measure tubing from the bottom of your reservoir to the fixing which will hold the tube on your flood tray. One thing to note is there should be a lid on your tank, and you will need to cut holes large enough for both tubes to pass through. Any light into your nutrients can help bacteria grow.
  8. Connect the tube to your water pump, and feed it through the lid and connect it to the inlet fitting.
  9. Attach a shorter length of the tube onto your overflow, so it sits inside the lid but clears the top of the water. This will help with oxygenation as excess circulates back into your tank.
  10. Fill your tank with the required amount of water and run the system. Check there are no leaks from either the inlet or the overflow.
  11. You can then install your timer, and get ready for your pots or Rockwool cubes to be added.

If you wish to use an air pump, be sure to use black tubing, and the hole in your tank lid is small enough to only let the tube through and no light.

When you are looking for a water pump, it is advisable to wait until you have your flood table. If you opt for a 4 ft. X 4 ft. Flood table a 170 GPH(Gallon per hour) pump is suitable. If your flood table is 4 ft. X 8 ft. then a 300 GPH water pump will suffice.

Suitable Growing Mediums for a Flood and Drain System

Because the levels of flooding can vary when you use different growing mediums, it is useful to know which ones you have at your disposal.

  • Rockwool – these are suitable when they are in both Rockwool blocks and also when cubes are used in pots.
  • Coco Coir – This coco fiber is suitable to be used in both pots or in blocks
  • Hydroton clay pebbles – this growing medium is ideal for use in net pots. It should be noted, this won’t hold water as long, so your flood times will be more frequent.

Flood Cycle Times for Different Growing Mediums

Because each growing medium will retain different amounts of water from the flood cycle, these cycles can vary dramatically. Here are estimations of the flood and drain cycle times.

There can be several variables that will shorten or extend these times. Both plant types and environmental conditions can have a significant impact on growing media drying out. These times will be a good starting point of how you will need to set your timer.

Hydroton pebbles

These require frequent flood cycles. Although they don’t hold as much moisture as other growing mediums, they are hugely popular as they give good plant support. The most commonly followed cycles for this growing medium are as follows:

  • 15 minutes on – 15 minutes off
  • 15 minutes on – 30 minutes off
  • 15 minutes on – 45 minutes off

You will need to do some testing to make sure your Hydroton hasn’t totally dried out before the pump timer starts again.


The cycles for Rockwool can range between 3 – 5 hours. For this medium, plant size and the conditions of your growing area will have an effect. The flooding time will most likely be the same 15 minutes, but the time of no nutrients will vary. The best way to tell is to run your system and left your blocks at hourly intervals. When the block feels light and there no dripping moisture, then it is time for the next flood cycle. This can change as your plants grow, and they take up more water and nutrients.


This growing medium can have the most significant variable flood time because of how quickly it dries out. To find out, you need to see how quick the top 1/2 inch dries. You can easily see this as the material goes from a dark brown when it is saturated, back to a light brown as it dries. If you are using Boss Blocks, then the flood time can be from 3 – 4 hours depending on environmental conditions.

Ebb and Flow Advantages and Disadvantages


  • Low Cost – This is one of the cheapest systems you can build. There are many of the parts where you can improvise. Tanks and flood trays can be made from anything which is of a suitable size.
  • Easy to construct – Building an Ebb and Flow system is very easy. If you have something to support your flood tray, the hardest part will be the drilling of the holes for your inlet and overflow tubes.
  • Plenty of Nutrients – The way the system works makes sure all your plants receive sufficient nutrients and also oxygen. The overflow will prevent too much-standing water, so it isn’t possible for plants to suffocate.
  • Ease of use – When the system is running, you have done all the hard work, and all you need to do is maintain your nutrients at the correct levels and give your plants sufficient light.


Unstable pH levels – if your system fails in any area, or you add too many nutrients/ water, you can find your pH levels fall out of the optimum range. Additionally, if you top off with extra nutrients and the EC levels increase, you can cause nutrient burn, and there will be a buildup of salts in your system.

Breakdowns – the primary point of failure is your water pump. If this fails, you will only have until the next flood cycle is about to commence before plants start to die. Hydroton pebbles will be the fastest to suffer while Rockwool will give you the most amount of time. Manual filling can be a temporary fix, but you will need to replace your pump.

Best Plants to Grow in an Ebb and Flow System

While there are many things you can grow in an ebb and flow system, there are three types of vegetables that do really well. These also come in different varieties, so there is a little choice you can have rather than growing the same.


There are plenty of cucumber varieties that are ideal for an ebb and flow system:

  • Mini cocktail cucumbers – These are harvested when they are around 2-3 inches in length.
  • American Slicer type – These fruits are ready to harvest when they are around 7 – 8 inches in length. They are also resistant to disease and are very high yielding in a hydroponic system.
  • Dutch type (seedless) – This type is popular as they deliver the most abundant fruits of around 14 inches in length. They have thin skins, and there is no bitter aftertaste. This variety of cucumber is also resistant against powdery mildew that can affect other varieties.


This is one of the most popular vegetables to grow in any hydroponic system. However, several varieties excel in these conditions. Here are well-proven high-performers.

  • Salanova – This variety is one of the new trendy lettuces and is a good way of impressing family and friends. The unique thing with this lettuce is that it grows compact heads which are all uniform in their shape and sizes. You can purchase seeds which offer different colored lettuce, although this variety is a little more expensive.
  • Green Butter – This variety of lettuce is ideal for climates like Florida. It is strong enough to fend off downy mildew, and it is slow to bolt. It is a highly-reliable grower and delivers consistent yields.
  • Green Frilled – This type of lettuce can be ideal for warmer environments as it is quite heat-tolerant. It delivers plenty of flavor from its medium sized heads. This variety does grow a little slower than others.


These may need supporting as they grow, but an ebb and flow system are ideal for this as everything will be stationary. The best two types of tomatoes to produce are:

  • Cherry Tomatoes – There are a couple varieties of cherry tomatoes (Sakura, Flavorita), so either is ideal for an ebb and flow system. Both types have disease resistance properties while not being prone to cracks or skin splits.
  • Beefsteak Tomatoes – Two of the more popular varieties grown in commercial ventures are Geronimo and Trust. These are perfect for growing in an ebb and flow system as they deliver huge fruits, and are disease resistant. These hybrid varieties will require lots of potassium as they begin showing their fruits. These will definitely need supporting.


Any grower who is looking to get into hydroponics can find all they need in an Ebb and Flow System. They are super easy to build and very cost-effective to run. They also deliver some of the highest yields out of any system.

Almost anything can be grown in this system, and the three vegetables above are purely examples. You can easily mix and match any plants as they are all grown in their own pot of Rockwool blocks. The only hard thing is to make sure your nutrient levels are suitable for all the varieties you wish to grow.

An Ebb and Flow System is so easy to build and cheap to purchase materials for, there is little reason why any grower only needs to keep to one. Two or more of these flood and drain systems allows you to diversify on your plant choice, and each can be set up separately.