What is the Best Fertilizer for Hydroponics?

As hydroponics grows without soil, plants miss out on a vast number of nutrients that are contained in the ground. This is where hydroponic nutrients come into play and are replacements for all of the micro and macronutrients that are found in soil. There are two types of fertilizers you can use, liquid or powdered, and these can come in organic or non-organic varieties. Here we will take a quick look at which one is the best, and also the possibility of making your own instead of buying.

What is the best fertilizer for hydroponics? The best fertilizer you can choose, needs to be one you are most comfortable with as a grower, and at the very least, the best fertilizer for hydroponics is one that delivers all of the micro and macronutrients at each phase of a plants growth.  

If you want to find out the best fertilizer choice you can make for your plants, or you want to find out whether to go organic or not, read on and all your questions will be answered.

What do Plants Need from Fertilizer to Grow?

Macro and Micro Nutrients

The three core macronutrients are Nitrogen, Phosphorus, Potassium (N-P-K), and these are absorbed in the most substantial quantities. Here is a quick breakdown of the role of each during plants growth:

  • N (Nitrogen): Responsible for leaf growth, Leaf color and providing proteins, amino acids, chlorophyll synthesis, and nucleic acid.
  • P (Phosphorus): This is responsible for the synthesis of plants RNA and DNA. It also dictates the proper development of Stems, flowers, roots, and seeds.
  • K (Potassium): The primary role is to synthesize proteins and carbohydrates, and in a smaller degree it helps develop stems, roots, and flowers.

Micronutrients are required for plant growth, albeit in smaller quantities than the above. These are Boron, Calcium, Copper, Iron, Magnesium, Sulfur and Zinc.

Fertilizer Types for Hydroponic Use

Hydroponics Unearthed eBook

Now we have seen what components plants need, we will take a look at powdered nutrients and the liquid type before taking a look at organic, and also how you can make your own.

Powdered Fertilizer

Although fertilizer in a powder form is customarily used in commercial scale hydroponics, there is nothing to prevent anyone from using these. One of the significant differences, when you compare them to liquid fertilizers, is, you are not paying for water to be shipped.

Powdered fertilizers come in different ratios for N-P-K, and the one you choose will depend on the plant types you are growing. An example being, the ratio will be very different for lettuce as it is for tomatoes.

With this aside, you will have three core mixes to fertilize your hydroponic system:

  1. N-P-K fertilizer mix
  2. Calcium Nitrate
  3. Magnesium Sulfate (Epsom salts – never buy with added dye or scent)

Your plants and crops will be pulling oxygen, hydrogen, and carbon from the water and atmosphere, so there is little need for worrying about these apart from making sure your roots are not waterlogged.

The N-P-K primary nutrients will be provided by your first fertilizer, and are then followed by your secondary nutrients which are your calcium, magnesium, and sulfur. The magnesium and sulfur are supplemented by the Epsom salts.

After this, all you need to worry about will be the micronutrients, and rather than purchasing a system that will automatically add these, we suggest monitoring your plant’s growth and dealing with any deficiency as it arises.

With these components, you can mix them all together, or you can add them to your system one by one, but the crucial part is making sure they are all thoroughly dissolved. The quantities you are adding will be on the product packaging, as will the amount of Epsom salts which will be included.

Liquid Fertilizer

Hydroponics Unearthed eBook

For many home growers, it is well-known liquid fertilizers hold the edge slightly over powdered fertilizers. This can be for ease of use because it is much easier to measure out than figuring out the ratios of powders to add.

Liquid fertilizers come in 1-2 or 3 part solutions and depending on your plants, or the phase of their growth, the amount from each bottle will be changed. Along with this, there is no adding of additional supplements because everything is already included.

There are many brands on the market, and growers prefer one brand over another. This, of course, is down to the grower who has found the best liquid fertilizer for their use. Mixing is as easy as adding to water and stirring it before you add it to your nutrient reservoir, and on most occasions, the quantity is per gallon of water which makes it easier than needing a weighing scale.

An often overlooked benefit of liquid fertilizers is that there is less chance of residue build-up in piping or water trays within your system.

Out of these two, a lot of it depends on the scale of operation. Buying in bulk for commercial farms makes more sense, and they will be geared up to face the minor problems which come with using this type of formula. Liquid fertilizers for many are highly convenient and eliminate a lot of the issues. Many also come with pH level buffers so there won’t be as much need to adjust pH levels manually.

Now, we will take a look at if it is better to use organic fertilizers and lastly, how you can make your own. There is a massive debate if hydroponics can be entirely organic, but, leaving that aside, you need to see what using organic fertilizers means for you, and how it affects plant growth.

Organic Fertilizers for Hydroponics

Although nutrients can be organic, it is difficult to get a full range of nutrients from one source alone. It is common for growers to blend two or more fertilizers which are organic to reach the desired levels. Base products often come from a concentrated fish emulsion that is then combined with liquid calcium. After this, there is the chance a source of organic nitrogen might be required.

The most significant downside of using organic nutrients in hydroponics, is that it can be difficult to reach high enough levels of nitrogen and calcium. What happens is that the systems rely on microbes which are found in the root zone to convert organic compounds into nitrogen sources which are ideal for plants to use. In many cases, this process doesn’t happen fast enough for the nutrients to be taken up by the plants.

Although there are many commercial products available which are organic based, the most reliable method for smaller farmers is to use vermiculture (worm farming). It should be noted, plants are none the wiser where their nutrients came from, and if you use inorganic, or organic, they have no preference. Must of the debate about being organic is for the benefit of what we do to obtain the healthiest food possible.

Before Making Your Own Organic Fertilizer for Hydroponics

The best process a grower can use is as we have just seen, vermiculture. This is a highly effective way of processing raw materials into solutions that are fit for use in a hydroponic system. Materials such as manure, blood and bone, seaweed meal, fish meal, and limestone can all be mineralized.

The vermiculture process relies on two components. The vermicast process must be carried out all the way to completion, and then from this, all of the goodness needs to be extracted into water. Growers can purchases worm juices, but, many of these are already diluted and not balanced to use as a standalone solution.

Although many food scraps, weeds, and vegetation can be used, these end up containing lower levels of the nutrient than liquids being produced from high-mineral sources such as the fish blood and bone meal. Another area which causes problems is that of concentration because many organic solutions are not as concentrated as regular salt-based fertilizers. This can leave plants more vulnerable to disease while not growing vigorously.

Whilst this is fine for more experienced growers, who can detect nutrient deficiencies, and even then to adjust these, it might take the addition of further additives like humic and fulvic acid to aid in nutrient uptake.

DIY Organic Liquid Fertilizers

Here are two quick ways of producing organic nutrients for your hydroponic systems.

Worm or Compost Tea:

  1. In a 5-gallon bucket, place 1 pound of either compost or work castings.
  2. Fill the bucket with water and stir well.
  3. Aerate the mixture continuously. Aquarium air pumps are ideal for this.
  4. Sit the bucket out of direct sunlight for 3 days. Be sure to mix every day.
  5. Filter the liquid through a disposable filter to remove all of the solids.
  6. This compost or worm tea can act as your fertilizer.

Plant and Animal Byproducts

  1. In a 5-gallon bucket add one gallon of water.
  2. Add 1 1/2 tsp of fish emulsion
  3. Add 1 1/2 tsp of seaweed extract
  4. Add 1 tablespoon of blood meal
  5. Mix well and use as your fertilizer. Check for any sediment and filter is required.

Related Questions

Should I use Epsom Salts for hydroponics? Epsom salts are used to treat magnesium deficiencies, and not only for hydroponics. They are commonly used in soil based gardens also. Epsom salts consist of oxygen, sulfur, and magnesium (magnesium sulfate).

What is required for hydroponics? Aside from the N-P-K ratios, you need a consistent temperature between 50 -70 degrees for fall crops. Spring plants require 60 – 80 degrees. Additional oxygen is necessary for optimal nutrient uptake.

Can I use my hydroponic nutrients in the soil? Hydroponic nutrients will increase the potency of buds. Plants will also grow too fast. These shouldn’t be used in the soil as soil fertilizers shouldn’t be used in hydroponics.

Hydroponics Unearthed eBook

Can You Use Miracle-Gro in Hydroponics?

This question doesn’t really have an easy answer because there are a few variables at play. To be entirely sure if Miracle-Gro can be used in a hydroponics system, we need to see if it contains all the elements which plants need for proper growth.

There are also other factors which might determine, not only its effectiveness for hydroponic use but also its suitability. This comes from the fact Miracle-Gro needs to be dissolved in water before use, whereas hydroponic nutrients in most cases for hobby or home growers are already in liquid form. This in itself might cause problems with hydroponic systems, which we will see.

There is also a vast difference in price between the two, and this reason alone can help you see why people decide to opt for Miracle-Gro rather than more expensive nutrients. Again, we will quickly find out if this is justified, or it is a false economy.

Does Miracle-Gro Contain the Correct Nutrient Composition?

Too Many or Too Little Nutrients

When growing in hydroponics, we need to be sure everything the plants need is delivered to them. Roots are unable to reach out in search of nutrients because they are growing in a soilless environment. For any nutrient solution to be considered, there are two factors we need to think about.

Does the nutrient solution contain all of the elements which are required for robust and healthy plant growth, and are they in the correct ratios? Secondly, these complete balanced solutions will be running at an EC (Electrical Conductivity) strength for different phases of plant growth, type of plant, and also the type of hydroponic system you are running.

When looking at this, we need to see if Miracle-Gro contains everything plants actually require for proper growth.

Hydroponics Unearthed eBook

While not looking at individual crops, many hydroponic growers prefer ‘pre-mixed’ nutrients which only require being added to water. It is larger growers who have commercial systems which tend to opt for powdered variants and to mix their own. These ‘pre-mixed’ nutrients can be purchased in packs of 2 or 3 parts, and what this allows a grower to do, is alter the ratios for each phase of their plant’s growth.

When you look at Miracle-Gro, there is no option to do this as it only comes as a 1-part-solution, and already we can see there will be problems during some stage of plant growth. Miracle-Gro isn’t designed to be complete plant food, and it isn’t possible for regular fertilizer to deliver what plants want at each stage of growth.

What Elements does a Complete Plant Food Require?

As we have seen, Miracle-Gro isn’t designed as being complete plant food. However, hydroponic nutrients are designed to be complete plant foods, and to be ‘complete’ a nutrient solution must contain the following:

  • Nitrogen (N)
  • Phosphorus (P)
  • Potassium (K)
  • Calcium (Ca)
  • Zinc (Zn)
  • Sulphur (S)
  • Iron (Fe)
  • Copper (Cu)
  • Manganese (Mn)
  • Magnesium (Mg)
  • Boron (B)
  • Chlorine (Cl)
  • Molybdate (Mo)

There are secondary elements many of these nutrient solutions contain, and although not essential, they can be beneficial to plant growth. These are:

  • Nickel (Ni)
  • Cobalt (Co)
  • Silica (Si) and/ or Selenium (Se)

Out of this list, the primary three nutrients are Nitrogen, Phosphorus and Potassium. You will see this everywhere you look, but they will be related to most often as N-P-K. Without these, plants will die.

When you purchase hydroponic base nutrients, these ratios are displayed on the bottles. This is important because plants not only need the correct nutrients, they also need them to be in the proper ratios.

There are two stages a plant goes through during its life, and each of these requires a specific ratio of N-P-K for the best overall growth.

  • The Vegetative phase (growing): Nitrogen (high), Phosphorus (medium) and Potassium (high)
  • The Flowering stage (blooming): Nitrogen (low), Phosphorus (medium) and Potassium (high)

On an additional note: in the flowering stage, growers were led to believe the Phosphorus levels were to be much higher than is actually required.

Now, when we take a look at Miracle-Gro as a hydroponic solution, things take a downturn because there is no way to tailor any nutrient for your plants. This means they will be fed the same ratios of all nutrients through both phases of growth.

Hydroponics Unearthed eBook

When we take a look at Miracle-Gro, it is easy to see they are missing quite a few essential elements, a couple of which are Calcium, Magnesium, Sulfur, and Chlorine. With this in mind, we have two phases of plant growth where you can only feed your plants the same nutrients.

Even adjusting the quantities, elements are missing, and you will end up altering the compound levels in the fertilizer without a way of controlling them.

Nutrient deficiencies which occur from using Miracle-Gro can display symptoms like, younger leaves becoming distorted, staying small in size, and with dead areas from a lack of calcium. Magnesium deficiency symptoms are common in tomatoes where the older leaves develop yellow areas between the veins. This is very similar to leaves which wilt and yellow with dead spots that indicate a lack of chlorine being delivered to your plants.

Hydroponic Nutrients Vs. Miracle-Gro

As a quick example of how growers would use the two formula’s, here is how they would be added to a hydroponics system.

Miracle-Gro: Mix 2 teaspoons for each gallon of water, and then add 1 teaspoon of Epsom salts for each gallon. Mix until dissolved, and only mix what you will use because the effectiveness wears off. When combined, the solution will be blue. Check and adjust pH levels with the right solution.

Hydroponic nutrients: Using one of the most popular hydroponic nutrient packs, you would take the three bottles which make up the ‘Flora’ line by General Hydroponics, and consists of: Grow, Bloom and Micro. All instructions are on the bottles for ratios to be mixed for each phase of your plant’s growth.

Add to your solution, no need for dissolving or mixing, and it is easy to make as you need it.

These can be adapted for different hydroponic systems and plant types at all of their growing phases to obtain the maximum growth possible. When you follow the instructions as indicated, your plants will grow fine, and there is no need for adding any additional nutrients. Check pH levels, but these nutrients do come with an included pH buffer to prevent spikes or drops in these levels.

Hydroponic nutrients also contain chelated trace elements, and although Miracle-Gro has some trace elements, these might not be chelated because this occurs naturally in a soil growing environment.

Feeding Your Plants and Nutrient Problems

As we feed plants, nutrient solutions are taken up, and water evaporates with EC levels rising. When this begins to happen, plants will start lacking nutrients. To measure the concentration of elements in our nutrient solutions, we perform an EC check, and although it isn’t possible to test for the concentration of each component, we can test for the overall PPM quickly.

When we submerge a digital PPM meter into the solution to take a reading, a normal EC level should range from 1000 to 1500 ppm. This can vary due to crops being grown, and also at the stage of their growth because you do need a higher PPM as your plants increase in size.

As this feeding pattern changes, pH levels can change, and it is crucial to adjust levels to balance them out. If the pH levels drift too far in either direction, our plants will start to suffer from nutrient lock-out where they are unable to absorb.

Again going back to Miracle-Gro and it being a 1-part-solution, we are unable to change any of these levels individually, and all that can be done is to increase or weaken the overall EC of the solution. This might sound as if we are doing the right thing. However, the individual nutrients will all be adjusted, instead of us being able to change specific areas.

This can result in using a weak solution, and because the ratio of certain nutrients was low to start with, our plants might be receiving next to zero. Additionally, the feeding time that is recommended when using Miracle-Gro in conventional gardening is every 7 – 14 days. With a feeding schedule more frequent than this in a hydroponic system, it can be, you overfeed your plants with a supply of nutrients which isn’t complete.

Other problems can stem from using Miracle-Gro because you are unable to control the levels of nutrients delivered, and it lacks in certain nutrients. The issues can be as follows:

  • Underfeeding: Plants appear pale due to a lack of nutrients.
  • Overfeeding: You will be overfeeding certain nutrients without being aware. This leads to either nutrient burn, where your plants end up with dark spots on the tips of their leaves. Or, nutrient lockout where your plants are unable to absorb the nutrients they need.

When there is a nutrient deficiency, which will occur using Miracle-Gro further into a plants growth. Plants begin to droop, and if you have fruits, these can start to drop before they are ready. This happens because there aren’t the right nutrients in Miracle-Gro to support and sustain the production of fruit. Many hydroponic growers have tried Miracle-Gro and state that everything can appear okay in the first few weeks, but from this stage onward, it can go downhill where buds will not flower and end up falling.

This is though, dependent on your crop, but it shows there is a severe lack of nutrients at this stage of your plant’s growth.

Chasing your pH

As we know, pH levels will change when nutrients are added, or as water levels drop and the EC levels rise. Most often, hydroponic nutrients come with a pH buffer which helps maintain pH levels, although they do still need checking, and adjusting as required.

Miracle-Gro on the other hand, comes with no pH buffer, and the majority of Nitrogen (N) that is provided in the fertilizer is derived from urea. As a result, pH levels can drop significantly in your solution, and unfortunately, you have no way to adjust Nitrogen levels in a Miracle-Gro solution. Using a weaker concentration is not an answer because all other trace element levels will also be lowered, and can lead to many other problems.

Miracle-Gro and the Kratky Method

We have seen that Miracle-Gro much like other regular fertilizers isn’t suitable for hydroponic systems. Systems such as hydroponic drip or aeroponics systems can become clogged in nozzles and pipes due to the solution not being fully dissolved. There is then the lack of nutrients, and the inability to change the N-P-K levels for different phases of plant growth, and salt build up that can occur quicker than if using the proper nutrient solutions.

With all of this information, we can easily say not to use Miracle-Gro at all, but, there is one area of hydroponics where you can use Miracle-Gro where none of these problems should arise or cause too much concern.

This is with passive hydroponics. For anyone who is looking for an effortless way to grow, so they can have a hands-off experience, or they are looking to venture into hydroponics but want to save on the expense until they are confident. This can be an ideal introduction, and because Miracle-Gro costs next to nothing, and can be found anywhere, there is nothing to lose.

This passive hydroponics system doesn’t use any electricity, pumps or air stones, and can be placed outdoors in a growing area, or indoors if you have the right grow lights.

The Kratky method was developed in the University of Hawaii by Bernard A. Kratky (horticulturist), is super simple and can be ideal for growing lettuce, spinach or herbs. Plants like tomatoes or anything similar won’t grow to their full potential.

How to Grow Using the Kratky Method 

Although this method is very straightforward, it does need steps to be followed. Here are the items you will require, and the steps you need to try this passive hydroponics method with Miracle-Gro.

Items required

  • Plant seeds of choice
  • Container with a lid you can cut – Styrofoam containers are ideal and easy to work with
  • Water and your Miracle-Gro/ Epsom salt mixture
  • A pH testing kit
  • Net pots and growing medium. Rockwool or coco coir is ideal for this system

Steps for system construction

  1. Taking the lid of your container, you need to cut holes large enough for your net pots to sit, so they are flush with the cover.
  2. Fill your net pots with the growing medium and plant your seeds
  3. Mix your nutrient solution and fill the bottom part of the container. Be sure to test the pH and adjust if necessary. Smaller plants require shallower or smaller containers.

How this passive hydroponics system works

Once the seedling starts drawing water and solution into the net pot, the water levels in the Styrofoam container drop. This then creates a space where roots can obtain their oxygen. Once the water in the container has gone, it is time to harvest your plants.

One of the crucial parts of this easy system is the container lid. It creates the area for moist air to circulate around your plant’s roots, and secondly it provides the required support for plants above water level. The final benefit is the space between the lid increases the containers aeration and allows heat to be removed from the nutrient solution.

For plants like lettuce and other leafy greens, this is one hydroponic solution where it is possible to use Miracle-Gro. For new growers, or as an introduction to hydroponics for children, there is nothing easier and as cheap to set up.

Conclusion

Armed with all the above information, you can see the use of Miracle-Gro is not recommended for use in hydroponics systems for quite a few reasons. Because it is a foolproof method of providing nutrients to soil-based gardens, this doesn’t make it ideal for hydroponics no matter what levels of concentration you use.

If your system becomes clogged and your solution flow is restricted, this has far more implications than merely flushing your system. Plants will be starved of nutrients and will no doubt suffer before you spot there is something wrong. You will also see toward the end of your plant’s growth, they lack the fullness and yield they deliver when using the proper nutrients which are designed for use in hydroponics.

One final thing to consider is the acquisition of General Hydroponics by the company who owns Miracle-Gro, via one of its subsidiaries, Hawthorne Gardening Co.  If Miracle-Gro were a decent substitute for a hydroponics system, they would no doubt have either marketed Miracle-Gro as such, or would have produced a variant which was suitable. Instead, they bought the most highly-regarded nutrient manufacturer. Is this a move to produce their own brand of nutrient, or is there another reason why they have purchased this company, along with the many other companies in this field?

Until the day arrives, growers are far better leaving Miracle-Gro for soil based gardens or using it in the Kratky method for some hands-off hydroponic gardening. There is too much at stake with your system and your plants, to advise using a lower quality and cheaper form of fertilizer as a replacement for hydroponic nutrients that are proven to work.

Hydroponics Unearthed eBook

Can You Use Regular Fertilizer for Hydroponics?

Regular fertilizers are much cheaper to purchase than hydroponic nutrients, and for this reason, many new growers consider using them in their hydroponic systems. On paper, this seems all well and good, but there are reasons why this might not be the best solution.

Can you use regular fertilizer for hydroponics? Yes, it is possible to use regular fertilizer for hydroponics, but in reality, you shouldn’t. Regular fertilizers lack many compounds that purpose-built hydroponic nutrients contain, and they can cause problems at different stages of growth.

If you are considering using regular fertilizer in your hydroponic system, you should read the information below because a couple of questions are answered as for why this could be a big mistake.

Understanding Plant Nutrition

Nutrients in conventional growing

Before even considering using regular fertilizer as a replacement for hydroponic nutrients, every grower needs to understand what plants need for proper plant growth. The first nutrients are non-mineral such as oxygen, carbon, and hydrogen, where carbon dioxide and oxygen are received from the atmosphere, and water providing the hydrogen.

All these are created during photosynthesis which all plants need to do to survive.

In the cycle of life, dead things fall to the floor and are broken down which returns all of the nutrients back into the soil. If the earth is lacking in nutrients, or they are growing in container gardens, gardeners can supplement the missing nutrients by adding fertilizers.

Hydroponics Unearthed eBook

Fertilizer and Nutrients

All fertilizers need three primary nutrients, and when you look to purchase any form of fertilizer, you need to check the packaging to ensure they are included.

Nitrogen (N): This helps make plant cells and chlorophyll (green leaves) which is required for photosynthesis. Nitrogen makes up between 40 – 50% of plant cells dry matter and promotes healthy foliage, and proper plant development through root absorption. Nitrogen levels are increased in growth nutrients.

Phosphorous (P): This is needed for photosynthesis, and a plants root development as well as when the plant blooms. Another function is the creation of nucleic acid which is vital for any living cell. This is important all through a plants growth, but uptake is increased during the flowering phase.

Potassium (K): This is also required for photosynthesis, and protein and carbohydrate creation. It also helps with a plants internal liquid movement in the roots and stems. This compound aids in overall fruit quality.

There are many other minerals and trace elements which are included in fertilizers, but their impact will be less than the three mentioned above. You can also see each of these can be tailored for different stages of plant growth.

It is for this reason, many hydroponic nutrients are sold as a 3-part solution, and each is used at a specific time as a plant is growing. Regular fertilizers are unable to do this because they are just a mix of nutrients and trace elements used as a supplement of what is already in the soil.

Because there is no soil in hydroponic systems, a regular fertilizer can leave plants lacking in some areas while overloading them in others.

What Should Hydroponic Fertilizers Contain?

To make sure your plants receive all they require, the following elements should be in the fertilizer you choose to purchase. It should be noted there can be different varieties of fertilizer for different plant types, so levels of certain nutrients will be higher or lower, and in most cases, this will be the N, P, K ratios which differ.

Hydroponics Unearthed eBook

These two lists cover the essential elements of what needs to be included.

Macro-nutrients

  • Nitrogen (N)
  • Phosphorus (P)
  • Potassium (K)
  • Calcium (Ca)
  • Sulfur (S)
  • Magnesium (Mg)
  • Iron (Fe)

Micro-elements

  • Manganese (Mn)
  • Boron (B)
  • Zinc (Zn)
  • Copper (Cu)
  • Molybdenum (Mo)

Regular Fertilizer and Hydroponic Salt Buildup

There are small amounts of salts present in all nutrient solutions. If the compounds are not set at specific levels for use in a hydroponic system, there will be an increased accumulation of salts and minerals.

What happens is when the growing media is repeatedly soaked, and there is evaporation occurring before the plants have a chance to be absorbed by the plant’s root system. On each feeding cycle, small amounts are left behind once the cycle has ended.

Moisture evaporates and leaves behind these minerals, which includes these salt particles. The EC (Electrical Conductivity) increases in the growing media and on the root system. Once this happens, there is an increase in osmotic pressure on the root system which prevents osmosis, and the plant’s ability to take in water and nutrients. To stop this happening make sure to regularly test the EC of your solution – we’ve written a full guide to testing can be found here.

Regular fertilizers are not balanced so there can be an excess of these salts remaining. Plant growth can be retarded, and they darken and harden. In more extreme cases, roots take on a burnt appearance as they slowly die.

Flower Drop Using Regular Fertilizer

Aside from the visible salt build up which can be seen as white crystals forming on top of the growing media, and around pipes and pots in the ebb and flow systems. There are severe consequences for the plants themselves as a result.

Because a regular fertilizer doesn’t have the increased levels of N, P, and K as you find in a 3-part nutrient pack, and the EC levels will rise with the salt build up as mentioned earlier. Plants can quickly suffer from vital mineral deficiency. This, in turn, causes slower plant and fruit development, and causes this ‘flower drop.’

Flower drop can also be caused by water stress which comes from high EC levels and lack of irrigation. As we saw, both of these are symptoms of salt build up from using unbalanced nutrients.

Testing for Increased EC Levels

Regardless of what fertilizer you use in your hydroponic system, you should periodically check the EC levels of your nutrients. This can help forewarn you of any salt build up. The EC of your nutrient solution should not vary much as it flows through your plants rooting systems. If you have an EC which increases as it flows from your plants, it is a sign you have a potential salt build up problem.

Higher EC levels indicate there is more salt in the water, as an example, distilled water doesn’t have an EC level because it contains no salts.

Preventing Excess Salt Accumulation

Minimizing excess salt accumulation in a system helps growers avoid potential problems. So, by paying attention to feeding schedules and how it affects growing plants and root zones. There are many products which are highly concentrated or imbalanced. Regular fertilizer being an example of an unbalanced fertilizer for hydroponic use. It can be easy to increase levels in certain elements in the root zone of your plants without realizing.

Too much fertilizer often leads to not only all the problems mentioned but also wasted nutrients and lower yields overall. When you research what nutrients are required by the plants you are growing, you can choose, or formulate your own nutrient solution which delivers the right amounts of every element your plants need for a healthy growth phase.

Feeding schedules might need decreasing, so there are less evaporation and more uptake from your plants. Choice of growth media can also help to minimize these salt buildups, so a growing medium which offers good drainage is required.

Conclusion

With all of the information above, you can see that using regular fertilizer in hydroponic systems doesn’t really offer any benefits aside from being cheaper alternatives. Price alone should be no reason to opt for one nutrient solution over another.

One final thing which hasn’t yet been mentioned are pH levels when you add nutrients. A regular fertilizer can drastically raise or lower your pH levels, whereas, purchased nutrients or fertilizers which are explicitly designed for hydroponics often come with pH buffers built in. You can learn how to test the pH levels of your setup with our handy guide.

Regular fertilizers are an all in one solution, but as we already know, there is no all in one solution when it comes to hydroponics. To get the best from our plants, we need to provide them with the best of what they need, and choosing a good liquid nutrient solution can help prevent all of the problems above from using regular fertilizer.

Related Questions

Can you make organic hydroponic fertilizer?

Yes. Take 6 ounces of seaweed and wrap it in a piece of cheesecloth and tie it with twine. Soak for 5 days in 5 gallons of water in the sun. Add 1 teaspoon of Epsom salts for each gallon (5 spoons). Add all or 1 gallon at a time to your hydro reservoir. We’ve laid out our favourite DIY hydroponic nutrients in this article.

What is the best fertilizer for Hydroponics?

Commercial farmers might opt for dry fertilizers and mix their own. Hobby growers tend to choose the liquid variety which is already blended and more convenient. 3-1-2 NPK ratios work well.

Do organic nutrients make hydroponic food healthier to eat?

No, although plants need these nutrients and minerals, they have no preference as to where they come from. To them, organic is precisely the same as non-organic varieties. Organic nutrients are more about making us feel better where they came from.

Hydroponics Unearthed eBook

Can Hydroponics Grow Everything?

There are countless numbers of people, who are either just starting hydroponics, or considering giving it a go. This can be for any number of reasons, but the main aim is to grow vegetables or specific plants at home rather than purchasing them from the supermarket.

One question which passes through most people’s mind is what can be grown, and what isn’t possible using hydroponics.

The answer is straightforward, but the results tell a very different story.

It is possible to grow almost everything hydroponically, but once you reach some types of plants, it isn’t feasible. Some things will grow, but they are actually hindered in their growth when raised in a water-based environment.

Here we will take a look at what can be grown, what shouldn’t be attempted due to various reasons, and we will also look at a couple of high-value crops you can grow in a hydroponics system that might surprise you.

Factors That Can Determine What Should Be Grown Using Hydroponics

Before delving into what we can grow, and what is best left to other growing methods, we will look at what factors are involved for either decision.

All plants grow by different means, and if these are mixed in a hydroponics system, it won’t be possible to tailor the nutrients to match each variety. Even if you separate nutrients, the overall growing conditions might suit some plants, such as warmer climates, or you have ones that prefer a cooler environment.

Hydroponics Unearthed eBook

There are shallow rooting plants and vegetables which are ideal, and then you have deep rooting tubers which require lots of depth and plenty of support. Things such as potatoes, carrots, and turnips among others can be grown when the conditions are tailored for them, but you can find they don’t taste any better than the varieties you can purchase.

Vegetables of this type also take up more space in your system, although they can be grown if you so wish.

In the same vein are vegetables like squash, zucchini, and corn. All these can be grown, but again, these are not suitable because they are surface growing vegetables and spread outward. This makes any hydroponics system unfeasible for vegetables of this type.

Trees are pretty big, and on trees comes fruits. But, once again, these can be grown using hydroponics. However, there are plenty of trees which are too big, and it makes no sense for any grower. But, there are some fruit trees which make very real sense to grow in a hydroponics environment.

Mother Nature has one thing up her sleeve which we can’t mimic as passively, and this is pollination. There are many plants which have both male and female flowers. These become labor intensive because there won’t be any bees inside your hydroponics environment, and learning how to manually pollinate plants can become a painstaking task.

One other factor which needs considering is, if you are growing indoors, or you have an outside area. Some vegetables can’t grow as easily under grow lights as they can outdoors, but because you have limited space, taller crops make very little sense.

To summarize all this, you can grow whatever you wish, but the most significant limiting factor is the practicality of doing so.  

Now, we will look at some of the best things you can grow in hydroponics in certain conditions.

Indoor Hydroponic Growing

Indoor hydroponics systems are used for a multitude of reasons. It can be that the local weather is harsh and growing outside doesn’t give plants much of a chance, or the growers live in the city and have no access to an outside area.

A system can be set up anywhere, as long as you provide everything plants need to grow. An indoor  hydroponics system need not take up too much space, and can even add to the aesthetics of your home. Here we will run through all you need for indoor growing, and which plants are ideal for this type of system.

Hydroponics Unearthed eBook

Space requirements

The space requirements can be as small or as large as you want. From a windowsill to a spare room or a basement, they all make ideal growing areas once you plan correctly. This is where plant size affects what can be grown, but for shorter plants, you can use shelving, or make use of an old table with lighting suspended from above.

One system that works effectively is growing towers because they use vertical space along an interior wall rather than flat growing areas.

Lighting

One thing plants need to do is photosynthesize. This they must do to survive, or they will wither up and die, no matter how well you have your nutrients mixed for them. Even if you have some natural light, this may not be sufficient, so you need to supplement this with grow lights.

With this, you now have one more element which is under your control, and with the correct types of lighting, you can deliver plants with the ideal amount without relying on the sun. Most vegetables grow best when they have access to 14-16 hours of light, and this can be sunlight or simulated (artificial) light.

There are many lighting options, and it can become confusing which ones to opt for. To make things a little easier, we have listed all the lamp types:

  • Incandescent lamps: inexpensive and can be purchased from hardware stores or nurseries. Sufficient for houseplants but not indoor garden systems.
  • Fluorescent lights: ideal for growing herbs and plants which are not light hungry. While inexpensive, they are not ideal for budding or flowering plants because they don’t deliver enough light.
  • Compact fluorescent lamps: these are bright while being efficient, and in some cases are better than the more expensive HID (High-Intensity Discharge) lighting systems. These are suitable for all plants, and because they run cooler, they can be placed closer to plants. Ideal for shelving systems.
  • HID lamps: efficient but expensive. They are the brightest, and one 1,000 watts grow light can throw out the same light as 50 forty watt fluorescent bulbs.
  • HPS (High-Pressure Sodium): These are one of the best bulbs you can use. However, they do have a few downsides. They are expensive to purchase, but they are economical to run. They produce a lot of heat, so they need to be used in air-cooled reflector kits. Lastly, they are not suitable for all growth stages. They don’t produce light in the blue spectrum which is needed for leafy growth.

Metal Halide (MH) bulbs are great to start plants off with, but when you reach the flowering stage, it is advisable to switch to an HPS bulb.

Lamp placement

  • 400 Watt: A five foot, or eight-foot square growing area needs lighting placed 1 to 4 feet from the plants.
  • 600  Watt: A seven or ten feet square growing area needs lighting set 1.5 feet to 5 feet from the plants.
  • 1000 Watt: An eight feet or twelve feet square growing area needs lighting set 2 to 6 feet from the plants.

Temperature and Humidity

Most plants and vegetables prefer temperatures in the 65 – 75F range. It might be the case you need heating or cooling depending on your location. This can be controlled by a cooling thermostat.

Humidity is also a crucial factor, and quick ways to see if you have a humidity problem are: brown leaf tips, your plants are looking puckered and withering, or they are losing their leaves.

To raise humidity, you can quickly mist plants daily, place a tray of water filled with lava rocks close to your plants, or make use of a humidifier or misting unit in extreme circumstances.

Plants Which are Ideal for Indoor Hydroponic Systems

  • Vegetables: Chard, Kale, Salad greens, peppers, carrots, onions, cherry type tomatoes, and beans.
  • Herbs: Basil, Parsley, Oregano, Chives, Cilantro, and Rosemary
  • Fruits: Blueberries and Strawberries

All other elements such as growing medium, nutrient mixes, and watering will follow the same patterns as other hydroponic spaces where you might possibly grow.

Everyday Hydroponic Vegetables

The list of vegetables which can grow in a hydroponics system is endless. We have seen which are ideal for indoor gardening, but when you have space in an outside area such as a hydroponic greenhouse, then the possibilities are endless.

It is easier to say you can grow everything, but vegetables which grow below the surface will need some extra care and tending to. Parsnips, potatoes, and radishes being some obvious culprits, although it is still possible with the extra effort.

We can go back to squash or vining plants, and in most cases, these are impractical for space reasons. However, beans are a great vining plant which takes really well to hydroponics without taking over. Seeds will germinate in around 2-weeks, and no special formulation of nutrients is required. They grow fast, and you will be picking plump beans like crazy.

Hydroponic Fruits

Succulent plant varieties don’t take well to hydroponics because they thrive in drier conditions. Water-loving plants make excellent choices to grow in your hydroponic set-up. Melons are one of the best examples of fruit which will thrive in this situation. If you have space and can support the plants as they grow, it is well worth checking cantaloupe and watermelons as two varieties.

Berries are a handy crop to grow, although out of all, it is the strawberry which is the easiest. One fruit which is very similar and can be grown using hydroponic methods is grapes, both varieties have been successfully grown so if you want some juicy table grapes or fancy a go at making your own wine, you only need a large area.

Almost all fruits can be grown in this manner, but it becomes astonishing when you learn you can grow banana’s in a hydroponic system. Such is their liking to this system, there is the Super Dwarf Cavendish variety which produces small dessert banana’s.

Citrus fruits are also capable of being grown, although these are in the dwarf tree variety rather than the full-grown versions. Either way, if you have space and can support the rooting system in your growing medium, there is no reason not to find an area to grow your own oranges, limes or lemon trees.

Lastly, you can follow in the dwarf tree vein and find small apple trees that can be successfully grown hydroponically. Again, as long as you provide all the tree needs in the way of nutrients, support, and light, then there is no reason you can’t have your own miniature apple tree orchard.

High-Value Hydroponic Crops

Although you might be growing hydroponically for your own pleasure, if you have an established system, nothing is holding you back from venturing out and growing crops which can bring in some extra money.

With this in mind, you do need to be selective in what you grow, and not offer what can already be found. Choosing crops which offer a higher return than lettuce or leafy greens make any venture worthwhile without added competition.

The following three crops can be profitable, but depending on where you live, there might already be a grower who is covering them. A little market research to what is, and what isn’t available can help make your decision, but for now, here are three great crops to ponder over.

Mushrooms

This has to be one crop which doesn’t pop up on most people’s lists of what to grow in their hydroponic systems. In a way, they are a contradiction because they require less light rather than needing more. This can make them a tremendous indoor crop.

Mushrooms require a soilless growing medium and moisture. You can purchase ready-to-use kits, or you can learn how to create your own mycelia. The only light mushrooms need is for triggering their fruiting (they don’t photosynthesize).

It is easier to purchase a mushroom kit which comes with colonized media (compressed sawdust, hulls or hardwood shavings). All you need to do is remove this from the packaging and submerge it into a bucket of water for between 6 – 12 hours.

These are then placed in a dark area which has a temperature of around 60 – 75F until it begins producing in several weeks. Once you have fully grown mushrooms and harvest, you can re-submerge your brick again and repeat the process.

Most kits can be used around four times. The fun is in doing the entire process on your own. You can purchase commercial mushroom spawn. Here are brief direction how to hydroponically grow mushrooms.

  1. Place mushroom spawn in a sterile petri dish. This will go to form mycelia.
  2. When this has happened, take a clear container and mix the mycelia with sterile grain or rice. This acts as the food source while the mushroom colonizes. You can see colonization when it looks white and has surrounded the grain substrate.
  3. Now mix the mycelia with some vermiculite and a little water until it is like clay. Form this into cakes.
  4. Place in a hydro tank with clay pebbles and an air stone
  5. The water shouldn’t reach the surface, so the cakes sit on top of the pebbles. Water should be over 60F, and well oxygenated.

Basil

Basil is one of the best herbs to grow using hydroponics. It is sensitive to cold climates so for indoor growing or heated greenhouses where you have a hydroponic system, it is ideal. Basil is only available for a few months of the year, so a fresh supply out of season is welcome by many a chef.

Hydroponic basil also comes with more flavor than conventionally grown, and you might find you can sell it by the pound rather than a few ounces here and there.

Basil delivers the highest yields in an NFT set-up, and likes things on the warm side. Temperatures around 70 – 75F and humidity at between 40 – 60 percent. They also love as much light as you can give them, be it sunlight or artificial lighting.

Strawberries

These are always a hit, even if you can only sell them to friends and family. In a hydroponics system, you have a good ten-month growing season, if not all year round. There are reports of yields being higher than conventionally grown strawberries to a staggering 4x what is usually harvested.

Red Gauntlet is a familiar favorite for indoor hydroponic growers which appears to deliver exceptional results. These are great for indoor systems when you are growing vertically, so a plant doesn’t need to give high yields because you have more plants in the same growing area.

Temperatures should be no higher than low 70F’s during the day, and no lower than the high 50’s at night. When you pick hydroponic strawberries, do this in the morning when they are at their sweetest.

Conclusion

As you can see, with space, time and the effort it is possible to grow most things using hydroponic methods. This doesn’t mean they should all be attempted. Because of the beauty of how the system works, when there is a need for plants to be grown using these methods, we already know it is possible, and all that needs changing are the means of supporting larger plants and trees.

Although growing some varieties is not practical for the home grower, it isn’t to say these things aren’t practical, in areas where it is hard to grow nourishing foods and fruits.

We can make fruit trees smaller to fit into our hydroponic systems, but the time will come when the systems become larger to accommodate full-sized trees.

Hydroponics Unearthed eBook

Is Hydroponics Really Good for the Environment?

As an alternative method to cultivating and growing plants, hydroponics is an industry that is blossoming into the mainstream gardening niche. As interest in hydroponics increases, so do the questions regarding its sustainability and effects on the environment.

Is hydroponics really good for the environment? Yes, hydroponics is good not just for the environment, but for several other reasons such as higher yield, water conservation and the removal of pesticides and herbicides.

What Is Hydroponics?

Before delving into the many benefits of hydroponics, let’s explore what exactly hydroponics is first. The simplest explanation is hydroponics is gardening without soil. Plants are grown in sand, gravel or liquid with nutrient-rich solutions as ‘food.’

While the popularity of hydroponics is growing rapidly, it is not a new concept, by any means. The floating gardens of the Aztecs and the hanging garden of Babylon are two examples of ancient hydroponics.

Hydroponic gardens are maintained through a special system – either purchased or built by hand – that allows the roots of the plant to come in direct contact with the nutrients and oxygen that it needs to grow.

5 Environmental benefits of Hydroponics

1.Higher Production

There are two reasons for the higher production in hydroponics than in soil-based plants. Both come down to space. Outdoor gardens require a lot of land, whereas hydroponic gardens can fit into the smallest of apartments.

Hydroponics Unearthed eBook

Furthermore, the roots of the plants have access to all the nutrients they need in the reservoir tank. The roots won’t need to expand or stretch out in search of food, meaning you can grow plants much closer, resulting in a higher yield.

2. Saves Water

With a worldwide water crisis on the horizon, saving water is at the forefront of everyone’s agenda. Hydroponics is the perfect solution for reducing wasteful water consumption. The plants are hydrated by a nutrient-rich water solution that can be reused for weeks at a time.

3. Less Land Erosion

Common estimates say that the earth is 71% water. That leaves 29% of earth’s surface as land, over half of which isn’t habitable, let alone sustainable for farming and gardens. When land is used for gardening, the soil must constantly be tilled and eventually, that spot of land becomes useless.

Some consider hydroponics to be the farming of the future, as the idea of inhabiting other planets grows. There isn’t any viable soil in space.

4. Reduced Use of Pesticides

While hydroponics isn’t completely insect-free, there are significantly fewer pests involved in soil-less farming, as most pests tend to need the soil to survive. Pesticides are not only harmful to the environment, but they can also be harmful to people – either through air exposure or ingestion.

Given the way plants are grown in hydroponics, weeds don’t have a chance to grow.  This reduces the need for any herbicides, which are used to kill weeds. It also removes any physical labor in pulling out weeds.

5. Works in Any Climate

Hydroponics Unearthed eBook

Depending on where you live, the ground could be frozen for half the year, making outdoor gardening a six-month Spring/Summer activity. Hydroponics allows you to grow plants regardless of how wet or dry your climate is.

Common Hydroponic Systems

There are 6 main types of hydroponic systems – wick, continuous drip, Ebb and Flow, deep water culture, nutrient film technique and aeroponics. All the systems involve a reservoir of nutrient-rich solution underneath a tray or basket where the plants are growing and each uses a different technique to feed the solution to the roots.

  • Wick

The wick system is the most rudimentary system. It uses a wick — a rope or piece of felt, for example – to draw the solution toward the roots. The solution is then absorbed by the roots directly.

  • Continuous Drip

The most widely used system, the drip system uses a timer that is connected to a pump that drips the nutrients onto the plants at a pre-set time. The drip method ensures that the plants aren’t drowned in the solution.

  • Ebb and Flow

The ebb and flow system has a pump as well, but the pump temporarily floods the grow tray with the required nutrients and then catches the run-off back in the reservoir, which is then recirculated at the next feeding.

  • Deep Water Culture

The most low-maintenance of the systems, the plants are housed in styrofoam containers on a platform above the solution. The platform is continuously immersed in the solution. This system works best with small plants that grow quickly, such as leaf lettuce.

  • Nutrient Film Technique

NFT for short, the nutrient film technique is a little different from the others. The plants are held in net pots high above the reservoir in a channel and the solution flows directly over the roots via a pump. The solution then drains back into the reservoir for reuse.

  • Aeroponics

Like NFT, the plants in the aeroponics system are held above the solution in baskets.  A timed pump lightly mists the roots on a schedule. The pre-set feature is what makes the aeroponic system the most technologically advanced.

Aquaponics

It would be remiss not to mention the practice of aquaponics – the combining of hydroponics with aqua farming. This technique uses snails and other fish to fertilize the solution that is then used to feed the plants.

The symbiotic relationship between the animals and plants allows for efficient, environmental-friendly gardening where the animals purify the water and their waste provides food for the plants.

Which Plants Work Best with Hydroponics?

You might be surprised to know that you can grow more than just vegetables in your hydroponic garden. The best plants that work best in hydroponic systems are ones that are durable and fast growing. When you first begin indoor gardening, it is best to start with the easiest plants to prevent becoming frustrated and giving up your dreams of having an indoor garden altogether.

The three types of plants mostly found in hydroponics gardens are:

  • Vegetables

The best types of vegetables that grow in hydroponic gardens are leafy vegetables (spinach, lettuce) and vine plants (tomatoes, technically a fruit.) While it is possible to grow root vegetables such as potatoes in hydroponic systems, it takes extra care and experience.

Vegetables grown hydroponically tend to grow bigger than those of the soil-based method because the plant has to exert less energy in reaching out to its nutrients. The nutrients are fed directly to the roots, giving it more energy to grow quickly and at a larger pace.

  • Herbs

Who doesn’t like to use herbs to add flavor to their homemade dishes? Hydroponics is a great method of growing thyme, basil and oregano, to name just a few. The herbs can be pruned as needed to encourage growth, but it’s not necessary.

One benefit of growing herbs in your indoor garden is you will be assured that they are truly organic and pest-free.

  • Houseplants

Yes, even some houseplants can be grown using hydroponic systems! The best way to grow houseplants indoors is by using the hydroponic system that entails hanging the plant and misting, which ensures the roots won’t be oversaturated.

The best houseplant for hydroponic gardening is the spider plant. The advantages to hydroponic-grown houseplants are reduced allergens in the air and mold prevention.

While herbs, vegetables and houseplants can all be grown hydroponically, they should all be in their own separate systems. Herbs typically can be grown together, but mint does best in its own system, as the roots need more room to grow than other herbs.

What About Fruit Trees?

While vegetables and vine fruits such as tomatoes are the most common plants grown in a hydroponic system, it is possible to grow fruit trees such as bananas and apples indoors.

It will take some finagling, patience and a lot of expertise, but with the right equipment (heat lamps and seeds) and extra room to grow, you can have yourself an indoor fruit tree.

Related questions

What Are the Disadvantages to Hydroponic Gardening?

There is something to consider before beginning your hydroponic garden. And that is how reliable is your power source? Hydroponic gardens can fall victim to a power outage that could potentially kill all of the plants. Many of the systems rely on pumps, which need electricity to run.

So, if there is one advantage soil-based gardening has over hydroponics is that you don’t have to worry about power outages, but you do have to worry about mother nature.

Is Hydroponics Better Than Soil?

The answer to this question comes down to preference and the reasons you are considering hydroponics. If your climate is the main reason for your desire to garden indoors, then yes, it is better than soil because with hydroponics, you don’t have to consider frozen ground/soil.

Plants grown using hydroponics instead of soil-based grow quicker because the nutrients are delivered directly to the roots.

Are Hydroponic Plants Healthy?

Healthiness of hydroponic plants depend on what solution is being used to grow the plants. Soil is naturally rich in the nutrients necessary for plants to grow. The solution used in hydroponics is created to replicate that nutrition, but if you don’t use the correct ingredients, your plants won’t be healthy enough to prosper.

Hydroponics Unearthed eBook

Can Trees be Grown Hydroponically?

Hydroponics are a great way to grow a garden, as can be seen from the sharp rise in its popularity. There’s a lot of speculation about what exactly you can and can’t grow in a hydroponics system. So let’s look at trees and logistics of growing them hydroponically.

Can trees be grown hydroponically? Like the majority of other plants, trees can be grown hydroponically if you do it right. That also means that while you can grow trees hydroponically, you can’t grow all trees in a hydroponic system.

While it’s possible to grow a tree hydroponically, if you want to do it successfully you need to look at things like the species of tree you want to grow, the size of your set up, and the method you’ll use you grow your tree. We’ll go over the main factors you need to consider before you start growing a tree hydroponically.

What trees can and shouldn’t be grown hydroponically

You have to remember that when you grow a tree, you’re growing a long term plant. Some trees live hundreds of years, like oak trees, and they grow very large. Even if you have a big hydroponic greenhouse, it just doesn’t make sense to grow a tree like that. Nor is it likely even possible to keep a tree like that living in your set up for its lifetime.

Basically, full size tree species shouldn’t be grown hydroponically. Ever. Aside from all the other issues, their root systems don’t handle it well and often choke healthy roots.

So, if you really want to grow a tree hydroponically, what options do you have?

You still have plenty of choice, but you need to look for dwarf species. A lot of hydroponic gardeners prefer growing small, dwarf fruit trees like lemon and banana trees. These miniature trees still produce fruit, often the same size as regular fruit, as long as they’re cared for properly. As long as you’re growing a dwarf species, you have pretty limitless options.

Methods you can use to grow trees hydroponically

Hydroponics Unearthed eBook

If you want to grow a tree hydroponically, you can try the liquid culture approach. Chances are if you go this route you’ll end up switching your set up to one that uses a growing medium. This will help make up for the density and mass of the tree’s root structure.

Going forward, we’ll assume we’re talking about methods using growing mediums.

Flood and Drain

The flood and drain system is also commonly called the ebb and flow method. In this simple system the main container holds the plants and medium (if you’re using it). Then, usually by timer, the container is flooded slowly to a preset level before slowly draining the water and nutrient solution back out.

Drip irrigation

The drip method, or constant water drip (CWD), is more common for growing trees hydroponically. That’s due a lot in part to the fact that it’s more flexible and easier to adjust to the size of a growing tree. Basically, in a drip system there’s a portion that holds the plant and growing medium while a container underneath provides the nutrient solution. From there, you pump it a bit and let gravity take care of the rest.

Using different growing mediums

Because of the weight and size of the tree, using a growing medium is the only practical way to grow a hydroponic tree. When choosing your growing there are a few choices that stand out for tree growth:

Rice husk

Rice husks or hulls are made in the process of farming and preparing rice and the husks are then processed for use in hydroponics. They’re a natural substrate of medium weight, and they last through quite a bit of use before they start to degrade. Note: always ensure the rice husks have been boiled and processed to avoid contamination issues like fungus and disease.

Hydroponics Unearthed eBook

Vermiculite or Perlite

These are pretty common, lightweight mediums. Made from expanded mica and volcanic rock respectively, they’re often used together. However, because they’re so light it’s better to use them for smaller plants like seedlings and saplings.

Rockwool

Rockwool is made of rocks melted and reconstructed into an insulation textured medium. It’s a good solution for trees of any age and weight, plus it helps retain both water and oxygen.

Requirements for growing trees hydroponically

Once you’ve got your hydroponic system up to grade to handle a tree, you still have more work to do. Like basically any other plant, your tree will need nutrients, light, temperature regulation (and sometimes humidity regulation too), and more.  Here’s a quick rundown of the considerations and basics you’ll need to add in:

Lighting

Your tree will need plenty of like to grow, no surprise there. How much light your tree needs can vary, but expect to be providing a solid 8 to 12 hours daily. No, your regular house lights don’t count either.

You need to provide your tree with some special growing lights. That means you’ll need to invest in either metal halide lamps, high pressure sodium lamps, or LED growing lights. The good news is that the lights will help with your issue of keeping enough heat around your tree.

Temperature

With your lighting, you should have less work to do in maintaining heat. To be sure your tree is warm enough, keep a thermometer in your growing area and routinely check the water temperature. Remember, different species have different temperature preferences, but so do trees of different ages. Seedlings prefer being grown in a solution with a temperature between 70 and 75 degrees Fahrenheit. Older trees can tolerate a wider range, usually anywhere between 65 and 80 degrees.

Ventilation

Your ventilation doesn’t need to be a super advanced system, but make sure you’ve got adequate air movement. This helps your tree get CO2 to convert, and it gives the helpful bonus of preventing harmful mold and fungi.

Humidity

This is where you’ll need to do a little research on the type of tree you’re planning on growing. While many trees do well with an ambient humidity level, some have specific requirements or just plain do better at certain level. For example, the Meyer lemon dwarf tree can handle most ambient humidity, but it really thrives at 40 to 50%.

Future Transplants

At some point in the future, you’ll have to move your tree into a bigger container. It’s better to plan for this in advance and set up your system accordingly. Factoring in the weight of materials and ease of access in your system early on means an easier time when you have to transplant.

Nutrients

If you’ve already got an established hydroponics system, you’re no stranger to adding in a nutrient solution. Make sure your nutrient combo is right for the tree you’re growing, and always remember to start at lower nutrient levels and work up.

Testing

Yes, you have to test your pH and nutrient levels as well as practice proper maintenance. While you probably already knew that, the acceptable levels are different from other hydroponic plants. Most plants do well in a slightly acidic solution with a pH range between 5.5 and 6.5. That being said, always check for your tree’s optimal pH. As an example, an apple tree prefers a pH range of 5.0 to 6.5, while a crab apple tree needs a pH range between 6.0 and 7.5.

Pollination

If you’re already planning on growing a tree hydroponically, you may have wondered what you’ll do if you don’t have pollinators at work. Pollinators, like bees, naturally distribute pollen from tree to tree. If you’ve only been growing self pollinating plants like lima beans and peas, you’ve never had to worry about this before. To pollinate your tree, swirl a small paintbrush in the blossoms of the branch of another tree of your same species. Then transfer the pollen to the blossoms of your tree, and you’ve done it.

Related Questions

What are the easiest trees to grow hydroponically?

Trees are always going to be a skill level up from say, growing lettuce. That being said, some trees are easier. Meyer lemon dwarf trees, miniature cherry trees, dwarf banana trees, and dwarf apple trees tend to be less temperamental  for less experienced gardeners.

Can I use my hydroponics system to grow saplings you transplant into soil later?

Absolutely! Keep in mind when you’re using hydroponics for saplings only that while you won’t have to modify your set up as much as for a dwarf tree, you will need to make plans to safely change its environment without causing shock.

How long until my hydroponic trees produce fruit?

Hydroponically grown fruit trees will produce fruit regularly as long as you’re pollinating them. Just like any other fruit tree, if you start with a younger tree (and for a hydroponic system you’ll have to), you can expect to care for it for 2 to 3 years before you see any fruit. 

Hydroponics Unearthed eBook

What’s the Difference Between Hydroponics and Aquaponics?

For a few years, there have been two means of growing crops of all varieties without the use of soil. These are hydroponics and aquaponics, and while they both follow some very similar principles, there are a few differences between the two.

Both systems use a nutrient-rich water solution as the growth medium for everything the plants or crops need for nutrition. The most significant differences are how plants receive these nutrients. Because of this, considerable debate has been going on for a few years as the method, which is superior.

Here we will look at the differences, similarities, and difficulties of each type of system. We will also see if one does come out on top as a clear winner. First off, we will take a quick look at the basics of each, so we know where we are a level playing field while comparing information.

Hydroponics and Aquaponics: An Introduction and Comparison

Basics of Hydroponics

Hydroponics use nutrient-enriched water and depending on the system type, they use inert growing mediums such as pea-gravel or perlite. You can identify the different types of hydroponic systems such as aeroponics, ebb and flow, nutrient film technique and Wilma systems.

The nutrient delivery changes throughout the different systems, but the principle is the same, there is no soil used, and the roots have contact with these solutions. However, in an aeroponics system rather than the roots sitting in a body of water, a nutrient-rich mist feeds the plants as the roots hang in suspension.

In all the other systems, oxygen is introduced to the water via air stones. These are the same as ones used in fish tanks for aquariums. Hydroponic systems can also make use of grow lights where they can be taken indoors and run in basements, patios or any area where there is enough space to erect systems.

Hydroponics Unearthed eBook

Aquaponics: The Basics

Aquaponics is a blend of technologies. First, there is an aquaculture where fish are grown in tanks or fishponds rather than being caught in the wild. In this setting, the water becomes dirty and needs to be disposed of. This is an enormous waste of precious natural resources, while at the same time; it becomes harmful for the fish.

Next, you have the hydroponic way of growing which is ideal apart from the need to refresh the nutrients on a regular basis. Now, when you marry these two together, you have a closed loop system.

Plants feed off the bacteria in the fish waste and all of the nutrients it contains. This step in the loop cleans water from all elements toxic to the fish. At this point, water flows back to the holding tank where fish can grow in ideal conditions. There is still the need to oxygenate the water via the air stones as in hydroponic systems.

What Hydroponics and Aquaponics Have in Common?

Because the two systems are closely tied together, there are many similarities. Here is a quick rundown of what both Hydroponics and Aquaponics have in common with each other.

  • They are both agricultural methods to grow crops without the use of soil.
  • Both system types rely on water as being the delivery system for the plant’s nutrients.
  • All nutrients will be artificially provided to crops.
  • Both types of systems are stable and can produce higher yields than soil-grown crops.
  • Both growing methods suffer less from pest damage.
  • Water and nutrient levels are lower for each plant than when grown in conventional methods. There is less wastage and crops are delivered what they need rather than roots fighting to find nutrients.

Hydroponic Vs. Aquaponics an Overview

HydroponicsAquaponics
DefinitionCultivation of plants in waterCultivation using fish and plants in a closed loop system
Nutrient typeChemical nutrientsOrganic matter produced by fish waste supplies nutrients
Cost-effectivenessLess cost effective due to purchasing nutrients. Chemical nutrient costs are increasing due to mineral scarcity.Highly cost-effective as organic matter is used to supply nutrients. There is a natural balance.
Startup speedFast to start upThese are slower to set up than a Hydroponics system
Operating temperaturesAside from growing lights, the overall temperatures are lower to prevent the growth of bacteriaHigher temperatures are encouraging to induce growth of nutrient-rich bacteria
ProductivityHydroponics produce lower yieldsAquaponics produce higher yields. With an aquaponics bio-filter in place, growers can see even larger yields 
System unloadingThese systems require flushing at intervals. Nutrient-rich water needs replacing because of salt build-up, and where the solution becomes toxic to plants.As it is a looped system, nutrients pass around the system and are used. Only water from evaporation and feeding the plants needs replacing
Ease of maintenance These have a higher degree of maintenanceThese systems are easy to maintain 

Hydroponics vs. Aquaponics: The Advantages and Disadvantages

Hydroponics Advantages

There are many commercial growers, who turn to hydroponics as their preferred growing technique due to the levels of control, and that it can fit quickly and easily into their business models. This happens for a few reasons:

Consistent Costing

Costs will vary depending on system size, management and product sourcing in a hydroponic system. Nevertheless, these scale in relation to production and are more consistent, thus giving an element of predictability.

Financial stability can be found because accounting and ordering become easier. This isn’t just the case for commercial ventures, but also for home hydroponic growers. The hydroponic nutrients are manufactured, and prices will remain steady across all months in the year. Compared to Aquaponics, the amount of fertilizer that needs to be used can be estimated in a narrower margin than food and supplements that are required in an aquaponics system.

Hydroponics Unearthed eBook

Ease of Operation and Training

The learning curve can be much more natural with a hydroponics system. If there are additions to a system, the steps are straightforward and consistent. This can be from a home system to a commercial venture where training becomes more leisurely.

Because there are fewer elements in a hydroponic system, the operation can be much easier. Once you have lighting, nutrient levels and growing media sorted; there is not much else that needs tending to.

Space and Location

A hydroponic system can be virtually any size you wish. This can encompass one pot to multiple pot flood and drain systems and nutrient film systems. Because there is a tendency to grow indoors, and making use of grow lights, any spare area is a possible growth area.

Aquaponics, on the other hand, needs space for a fish tank, and although it is possible to use an indoor aquarium, this won’t equate to a large growing area. Grow beds can also be smaller in a hydroponic system as all they need is a six-inch deep bed to hold the pots compared to the required twelve-inch minimum for flood and drain systems in aquaponics.

Effective Use of Nutrients

Hydroponics gives growers ultimate control of their plants nutrients. Many of these are customizable for each plant type all through a growth cycle. Along with this is the control of the pH levels. As nutrients are adaptable, the water pH levels can be monitored, raised or lowered as needed by pH controlling chemicals. With this, the environment becomes more sterile in a hydroponic system than an aquaponics system.

Hydroponic Disadvantages

Time and Commitment

Like most things in life, you get out of it what you put in. Hydroponics is no different, and to obtain the highest possible yields, you do need to put the time in and have the long-term commitment. When growing in soil, plants can be left to their own devices for days on end. Mother Nature will take care of them, and regulates the plant’s exposure to what they need to grow.

In hydroponics, there is nothing of this, and it is the grower who acts as Mother Nature. Without the correct care and the right amount of knowledge, plants can quickly die. Things can be automated to an extent, but even then, they do require supervision on a regular basis.

Experience and Knowledge

Although it can be straightforward to learn, a degree of expertise and knowledge will be required. The principles can be straightforward, but it is when you run into growing problems where experience shines. Nutrient mixtures for plant types can take a while to learn, and knowing when you need to adjust the pH, or drain and flush a system can be elusive to newer growers.

Being Organic

There is no question; hydroponically grown vegetables can be healthier than store-bought varieties. However, some people argue it isn’t possible to grow hydroponic vegetables organically.

There are some methods, which are suggested to grow organically. These suggestions are using coco coir that has added worm castings, or organic nutrients made naturally from fish bones, alfalfa and cottonseed among other things.

Research continues, but eating healthy vegetables is the primary goal, and that is what hydroponics is good for, regardless of the nutrients not being organic.

System Failure and Electricity Risks

A hydroponic system relies on electricity to run. This could be for your grow lights, water pumps, and aerators to heating or cooling depending on your growing circumstances. The other main component is water, and as we know, the two don’t mix.

On most occasions, this isn’t a problem when precautions are in place. Additionally, because the use of electricity is the primary power source, if this stops for any reason; or equipment fails, you can have plants dying in a matter of hours if no action is taken. Pumps need to run efficiently to make sure plants have their nutrients, and lighting needs to be available for the correct periods.

Startup Costs and ROI

Depending on the type of system you want, you can spend a couple of hundred dollars as a bare minimum. You need growing pots, growing lights, pumps and timers along with your growing media and nutrients.

Once you have all this in place, your costs do come down dramatically, and all you need will be nutrients and your electricity. The ROI is seen as being long-term because of these costs, but once you begin growing, the initial investment can be easily covered and justified.

Disposing of Nutrients

This can be seen as one of the significant downsides to a hydroponic system. This is for the cost, and the impact it can have on the environment. Systems do need flushing because there can be a buildup of salts which turns the solution toxic for plants.

Aquaponic Advantages

Fish Food Replaces Expensive Nutrients

The primary input of nutrients in an aquaponics system is fish waste. To make sure there is enough fish waste is by feeding them fish food. Depending on the system size, the cost for the year can be the matter of a few dollars.

When you compare the cost of fish food to nutrients, the fish solution is the most cost-effective.

Aquaponics is More Productive

Once an aquaponics bio-filter is fully established in a system. Growers can see faster and more profound growing results when compared to hydroponic systems. Even without these filters, aquaponics still holds the edge in yield size.

Aquaponics is Organic

While hydroponics is all about using a sterile environment to grow, aquaponics is the exact opposite and uses the closed loop eco-system to full effect. With bacteria and worms being used to break down ammonia and solid waste that is produced by the fish, these nutrients are then passed to the plants. These systems are organic in every sense of the word, and if any pesticides were used, this would be immediately harmful to the fish.

No More Root Rot

In hydroponic systems, “Pythium” can run amok and cause all sorts of problems. In an aquaponics system, the onset of this Pythium that results in root rot is almost non-existent because the plants build up tolerances against it.

Aquaponics Disadvantages

Although aquaponics does have plenty of positives, there are a few downsides.

System Construction is Complicated

Compared to a hydroponic system, the construction of an aquaponics system is far more complicated. There is the addition of fish tanks that come with additional plumbing, and requirements for more space. One other aspect to that needs considering is the size of the growing area available, is in proportion to the size of the fish tank. Calculating the balance between the two can be difficult for new growers.

Compared to the grow beds of a hydroponic system where pots are used. Aquaponics uses grow beds that are almost double in height at around twelve inches, and these are filled with the growing media. Also there needs to be a bell siphon as the draining mechanism rather than letting water drain back through the pump once it is turned off between fill phases.

Cycling Time is Longer

Aquaponics systems create a closed loop eco-system, and because of this, it takes a while for pH levels to adjust as the water is continually pumping around the system. Systems should run without fish for a few weeks (up to six) before anything is planted. Even then, it can take a while for microbial populations to become stabilized.

Until these levels of bacteria have risen, yields might be lower than anticipated in the first twelve months. During this time until a system is running correctly, the water needs periodic checking for the pH levels.

More Points of System Failure

Hydroponics can have two main areas that can quickly fail. These are your nutrient levels and your water pumps. In aquaponics, there are now multiple areas where things can go wrong. Fish can die for no reason, and if all are affected, this means no nutrients are getting to the plants.

Power or pump failures can affect both plants and the fish in the same manner, and if these are, off for extended periods, then both elements will suffer.

Due to system size, aquaponics is more often carried out in greenhouses or under canopies. These can introduce other points of failure if temperatures change too much in either direction.

Higher Initial Costs

You can design and build aquaponics systems out of recycled materials, and some of the most popular are PVC drums or the larger caged totes that can be modified. However, even these still add more to the overall build cost compared to a hydroponic system.

Electricity costs for fish pumps will be higher because they run around the clock to keep the water moving which delivers the right environment for your fish. These costs will be offset against growing lights if they are being used in a hydroponic system.

Conclusion

Both hydroponics and aquaponics follow many of the same principles while the methods of delivery are very different. Apart from the addition of fish tanks, system designs can be used for both. If there were to be one means of soilless growing which was to be the winner, then aquaponics might inch in front due to the higher yields growers can expect to see.

For average growers who want a system around their home, much of the decision comes down to available space and practicality. Startup and running costs for both systems will quickly be negated once you begin growing around the year compared to visiting the supermarket for a supply of fresh, healthy vegetables.

Hydroponics Unearthed eBook

Does Pot Size Matter in Hydroponics?

Hydroponic growers have many things to consider. First is the type of system they will be using, what are the best nutrients, and are they growing indoors or outdoors. All of this can create an intricate balance to make sure plants receive the best of everything. One factor, which might be overlooked, is the pot size, and how it affects plant growth.

Does pot size matter in hydroponics? Yes, pot size does matter in hydroponics. Incorrect pot size can hamper growth, and bigger isn’t always better. There are different pot construction types; and other factors like temperature, space, and most of all the plants themselves to consider.

If you are struggling to know how to choose the correct size and type of pot for your plants and your system, carry on reading the information below so you can quickly select the right size and type of pot for maximum plant growth and health.

Choosing and Using the Best Hydroponic Pots for Strong and Healthy Plants

Determining Factors for Pot Size

To make sure plants are presented with the best opportunity to flourish, there needs to be a delicate juggling act by the grower in three distinct areas. When these are combined, they all help determine pots sizes to be used throughout plants growing cycles.

Space – This will be determined by the type of hydroponic system. Indoors hydroponics systems can have reduced area compared to outdoor systems. Not only would these restrictions be overall floor space, but height is something else to consider. When you have a height restriction, you will need to use shorter pots, and this equates to shorter plants.

Temperature – This variable catches many growers out when they are first starting. If you are growing indoors and using HID grow lights, or your plants are in an area of direct sunlight, you could find your pots drying out too quickly. To solve this, you might need to increase your flood time in an ebb and flow system, or you can opt for a drip irrigation system to prevent drying. On the other end of the scale, you have areas which are cooler. Larger pots can remain too moist, and with this comes suffocation and rotting of the roots.

Hydroponics Unearthed eBook

Plants – Your plants will be one of the most distinct areas that dictate pot size. If you are planting seedlings or cuttings, then pot size will be much smaller than when they are healthy growing plants. At this early stage, pots of around 4-inches are sufficient, and once their roots are taking hold, you can transplant up to pots of 6-12 inches to encourage fast root growth.

Basics of Growing Pots and Why Size Matters

All forms of gardening that use growing pot’s fall under the same rules. Growers will pot up their plants into a smaller container, and then transplanting them as they grow.

In hydroponics, the only difference being, this process of potting up is used to encourage plant growth, and also maximize growing space. Once nutrients hit the growing media, they need to spread across the surface so plants can absorb all they need. At this point, pot size comes into play for two reasons.

A pot that is too small will mean plants can be standing in waterlogged growing media for an extended period. This is not good, and roots can suffocate, and then if left, they can start to rot. Pots which are too large allow the nutrient solution to evaporate before the plant has a chance to absorb all the nutrients it requires fully.

Root growth is dramatically affected by pot size, and this is where transplanting helps with faster growth. Roots spread across pots in an outward fashion rather than searching downward, and because they are in containers, they quickly hit the side and can’t go any further. At this point, they circle back on themselves and start bunching up. Plants become root bound, and can’t take up nutrients in an efficient manner which leads to stunted growth.

In larger pots, roots tend not to seek out the sides of the pot, and their root growth becomes limited, again this prevents plants growing to their maximum because nutrients have further to travel before reaching the plant.

Using Different Sized Pots in a Hydroponic System

Once you have a hydroponic system, there is a limit to how many pots you can use for the space you have available. This can be even more restrictive if you are growing indoors and using grow lights. A simple formula can help to determine pot sizes you can use for a specific space.

The growing light can be the starting point, and for each 600W of light, you should use 50-60 liters of growing media. This can be sufficient for pots which will be placed in a 1.2 meter squared growing bed. For a bed of this size, you can use the following as a guide as to what pot sizes will fit into this area.

Hydroponics Unearthed eBook
  • 6 x 10L (3 gallons) growing pots
  • 4 x 15L (4 gallons) growing pots
  • 2 x 30L (8 gallons) growing pots
  • 1 x 60L (16 gallons) growing pot

As you can see, all of the above reach to 60 litres (16 gallons) of growing media. Now, we need to look at how this will equate to your plant size, so they obtain the maximum amounts of benefits. A growing pot should be 1 gallon for each foot your plant grows in height. Looking at the above information, a 3-gallon pot is suitable for a plant which is no more than feet in height. When gardening indoors, most of your pot sizes will be 3 or 4 gallons in size.

For outdoor growers, pot size needs to be considered due to atmospheric evaporation. When a pot holds the right sized plant, you can water less often. However, when a plant isn’t large enough, the roots won’t seek out the pot, and you will waste both growing media and nutrient solution because it evaporates before reaching the plant’s limited number of roots.

Perched Water Tables and Pot Drainage

Because of the way hydroponic systems work, nutrients and water are fed to plants at set intervals using a hydroponic timer. As a result, the pot’s drainage needs to be sufficient to allow time for oxygen to reach the roots. Pot shape or size has no bearing on how adequate nutrients enter or leave the growing pots; all this is down to the growing media you are using.

When a pot drains between fill cycles, there will always be a section at the bottom which remains saturated, this is known as a perched water table. Something many growers are unaware of is, water isn’t evenly distributed through a growing pot. There are capillary action and adhesion where water is attracted to particles. Because of these two factors, water defies the forces of gravity when draining (matric potential), and these forces increase the lower you go down the pot.

Pot height has a bearing on the air to water ratio, and regardless of pot size, these perched water tables will be the same when the same growing media is used. Depending on growing media in use such as coco coir, some growers add pebbles to the lower portion of their pots to aid drainage. With the principles of perched water tables mean this situation isn’t resolved, and what actually happens is the perched water table level is raised.

This addition of pebbles can prevent run-off from being sucked back into growing pots by the natures of capillary action, and this in itself helps plants get the oxygen they need.

Smart Pots and Air Pots

Pot size is crucial, and aside from wasting hydroponic nutrients from oversized pots, it is healthy root growth which is the most critical. Plants that don’t seek out the pot, or become root bound will not grow to their potential. There have been a few innovations in pot design, and these can significantly help with crop yields.

Smart pots – These pots are made of a porous fabric that allows nutrients to flow in and then to drain excess water. Water travels by capillary action from the wetter parts to drier parts, so there is less chance of perched water tables causing problems, and roots have the opportunity to grab the oxygen they need.

Other areas these Smart Pots can benefit is from air-pruning. Roots reach the side of the pot and stop, they no longer circle back on themselves and become root bound, but the plant sends out new feeder roots, these absorb nutrients faster which leads to larger healthier plants. If there is a downside, it could be larger plants might need additional support.

Air pots – These plastic pots have been developed over a decade, and their primary goal is air-pruning. The sides are constructed in a cone-shaped fashion which encourages roots to seek out the pot. Once they hit the side, they are air-pruned, and then new feeder roots are sprouted by the plant. Air Pots build on the features of Smart Pots and can increase yields by significant quantities.

If there were a downside, it would be highly efficient draining the pots have, so you might find you need to water more frequently.

Although these pots can drastically improve your plants, the same rules of pot size should be followed, but with the efficient air-pruning, slightly smaller pot sizes can be used to no detriment of your plant’s health.

Related Questions

Do Plants outgrow their pots?

Roots, which are starting to grow out of the drainage holes, is the first sign of a pot-bound plant. Healthy plants will outgrow their pots, and the best way to reinvigorate growth is to transplant your plant into one that is two to four inches larger in diameter.

How high does water go in flood and drain system pots?

Once you set your system, fill each pot three-quarters full of growing medium. You should run the system until water reaches the level of your growing media. This should be the maximum water height. If water rises above this level, add more growing medium before adding plants.

Can you reuse smart pots?

Smart pots are reusable once growing cycles or transplants have been completed. Before reusing a smart pot, they should be thoroughly washed and cleaned. The most important thing any gardener should do is make sure the pot is thoroughly dry.

Hydroponics Unearthed eBook

Can You Grow Avocado in a Hydroponics System?

When people think of growing in hydroponic systems, they tend to think of more popular vegetables and fruits like lettuce, peppers, tomatoes, and strawberries. However, with some careful tweaking, it can be possible to grow an Avocado tree in a hydroponic system.

Can you grow avocado in a hydroponics system? Yes, you can grow Avocado in your hydroponic system when you give them the right growing conditions to thrive. The major drawback being the size of the tree when it reaches maturity, but tackling this early on can give you bumper crops of Avocado.

If you are up for the challenge and you want to start growing avocado in your hydroponic system, carry on reading, and all will be explained about how you can have a healthy tree that won’t take up too much space.

Growing Hydroponic Avocado – Where to Start

One of the first things that you should know when starting to grow an avocado tree is, you should be looking at growing two, the reason being when your trees finally reach pollination. There are two types, type A which sheds its pollen in the afternoon and is receptive to being pollinated in the morning, and type B which sheds pollen in the morning and is responsive to being pollinated in the afternoon.

If you are growing from seeds, you should note your tree won’t give fruit of the same variety because they don’t breed as true to seed. When you have two types of avocado trees, these will grow and breed true to their variety.

With this in mind and the fact you will be running your hydroponic system for four years upward before seeing any fruits, you need to mimic everything for your trees as if they were growing in their natural habitat.

You will need warm temperatures and plenty of light. This is one reason why they are ideal for growing in sunny parts of the house or in an enclosed patio to avoid cold winter chills. One thing that is a must is your grow lights; these will need to be either LED growing lights, metal halide lamps or high-pressure sodium light fixtures. We’ve written a complete guide to grow lights here to help you understand what to look out for and get your head around the terminology.

Hydroponics Unearthed eBook

In the beginning pot size isn’t an essential factor, but it is discussed later as they do play a crucial part in the growth of your tree. The main thing is if you wish to grow from seeds or purchase trees which are already on their way. If you aren’t sure about what pot size to use, try our pot size guide. Trees taken from grafts are much better for growing fruit than ones which are grown from seeds. Varieties of avocado can be purchased directly from specialty retailers that deal with colder climates.

Steps of Growing From an Avocado Seed

If you decide to grow from seeds, you can find these online from tropical seed retailers or at a local nursery. Growing from seeds does take much longer, but there could be a higher sense of satisfaction when your tree starts sprouting up. 

  1. Buy an avocado and remove the large seed from inside. Wash off any of the flesh but preserve the brown skin on the seed. Pat dry and set it aside to dry for a few days.
  2. Avocado pits have tops and bottoms. Look for the end which is more pointed. You should also notice the base has a slightly flat shape compared to the top. This is crucial because if you place it the wrong way up, your tree will be doomed from the start.
  3. Place the seed with the larger end at the bottom inside an AvoSeedo floater and float the container in a container of warm water at around 65 degrees. Change this frequently.
  4. Within a few days a root will begin to form, and then from the top, the first signs of a tree will poke from the top.
  5. When roots are almost filling the container, it is time to transplant to a pot.

Dwarfing Your Avocado Tree

This is the actual secret into growing avocado trees in hydroponic systems. Fully grown trees can grow up to 80ft high, but when you dwarf your tree, it can be a more manageable size while still providing fruits. To do this, restrictions on the tree growing space need to be imposed, the available water and also the nutrients provided must be strictly controlled.

These three elements will be a juggling act to let the tree grow as fast as it can while stunting its growth, and making sure it doesn’t die. If you are purchasing from a specialist tree dealer, don’t try to save time by buying a larger tree, the smaller, the better so you can shape its growth.

The growing pot at this stage should be as small as possible, but large enough to carry the plant for its first 12-months. Eighteen inches (45cm) is an ideal size to start, and then you will need to increase the size. This growing space will dictate the size of your final tree, so once the roots are well formed, you can move to a five gallon (20-25L) sized container. As time runs on, you might be able to go larger in pot size so your tree can reach its full potential while remaining small.

The containers should be filled with either perlite, vermiculite or coco fiber. A flood and drain method will be the most effective because any growth of algae will be prevented. Other systems used can be a drip irrigation system and would need three emitters per avocado tree.

With either method, the crucial part is preventing the root ball from drying out. Likewise, when you are transplanting to the growing pot, be careful not to damage any roots. Avocado likes to have their roots carefully tended to.

Pinching will be a necessary step to keep your tree fuller and shorter. The terminal bud needs to be pinched out and as a result, the buds which are dormant along the branch spring into life. These branches grow outward rather than upward, thus keeping the shorter height.

Even with a shorter height, the dwarfed plant will still be producing full-sized leaves. The final height of your tree will be around four to five feet in height.

Modifying Your Hydroponic Growing Setup for an Avocado Tree

Two things which need controlling are the acidity (pH) and the salt content in the growing medium and the nutrient mixture. For optimal growth a pH of between six and seven is ideal, but salt content needs to be as low as possible. Dwarfed avocado trees don’t take to higher levels of salt, and this is one reason growers like the flood and drain because it helps to keep salts to a minimum. You can learn how to build a flood and drain (also known as ebb and flow) system with our comprehensive guide.

Hydroponics Unearthed eBook

In the early stages, your nutrient mix should be half strength and your pH levels controlled with a digital reader, our guide to measuring and controlling your pH may help here. Once your tree starts to get bigger and stronger, you can increase your nutrients to full strength.

Depending on the species of avocado, they might need a cold spell once they are at the fruiting stage. This can vary, and it will also affect how you control the temperature of your nutrient mix.

Although you can grow these trees indoors, the aim is to get fruit. Indoor trees might not fruit, so this type of project is more suited to a greenhouse where you can control the temperatures and the humidity. One final thing to remember is, even with a tree which is much shorter than a wild grown variety, it will need a form of secondary staking.

The hydroponic growing medium doesn’t have the same sort of support as the earth, and with the upper weight of the tree increasing, it can quickly force your growing pot to capsize.   

Related Questions

Does an avocado tree need full sun?

Because the trees herald from Mexico, they do prefer full sun, but they do need protection from the western sun over the first few years. Once they develop strong root structures and dense leaves to protect the bark, they become much better at resisting strong sun.

How often will an Avocado tree produce fruit?

A full-sized avocado tree can produce up to 300 fruit per tree when it reaches around seven years of age. They do sometimes have alternate bears and have a bumper crop one season, and a smaller crop the following season. Dwarf avocado might be different to in volume due to their more diminutive stature.

Will my avocado produce fruit?

Trees which are sold from grafts produce fruit quicker than ones which are grown from seeds. Growing from seed could take an extra three or four years before they bear fruit if not longer. When grown from a graft, you might see fruit after three to four years.

Hydroponics Unearthed eBook

Can Hydroponic Nutrients Go Bad?

Because hydroponics plants are grown without soil, the only way they can obtain their nutrients is through additions to their water supply. Bottles of nutrients are often purchased by the gallon to make it cost-effective, and as a result, they might be standing for an extended period. New users might be concerned, and they have wasted money purchasing larger bottles. Is this the case?

Can Hydroponic Nutrients Go Bad? The good news is, hydroponic nutrients won’t go bad. However, nutrients need caring for and using correctly. If you overdose nutrients, symptoms are nutrient burn, salt build up, possible plant death, and you might dispose of nutrients you think are bad.

If you see these symptoms and need to know how to put things right without throwing out your nutrients, it is possible to save your unhealthy looking plants, and also save your bottles of nutrients, so carry on reading and find out all the answers.

My Plants Look Sick, So I Must Have Bad Nutrients?

Why Are My Nutrients Separating in the Bottles?

When you purchase your nutrients, there is a chance you might not see any expiration dates on the bottles, although this does depend on the quality of nutrient and the supplier. You might think no expiration date is a bad thing, but it is the first sign that your nutrients won’t go bad.

Once you open your bottles and start using them, you might see precipitates forming on the bottom. These solids are nothing to worry about, and in most cases giving the container, a good shake is enough to dissolve them again, so they become suspended back in the mixture.

These precipitates are compounds which are less soluble than other nutrients, and when left standing, they recombine to form solids. Calcium is the biggest culprit for this. Storing nutrients in a cool dark area with the top firmly fixed is a good practice.

Hydroponics Unearthed eBook

Checking Nutrient Levels

We have determined nutrients don’t go bad for many years, and even then they might be okay to use. Having the correct nutrient levels is crucial because this is what provides your plants with the best chance of growth to their full potential.

Once you begin growing hydroponically, you will need to know what the optimum levels are for your plants, and this determines the levels of nutrients you will be adding. There are a few things that need checking when you come to mix your nutrients and add them to your hydroponic system:

  • Parts Per Million (PPM) – This is a standard form of measurement, but in the world of hydroponics, it is a measurement of the total dissolved solids in your nutrient mix. It can also be used to measure how much CO2 is in the atmosphere.
  • Electrical Conductivity (EC) – This is the measurement of how conductive a solution is. Using an EC meter, an electrical voltage is passed to your nutrient mix and reads the how high the conductivity from mineral ion motion is being produced. If your EC levels rise too much, it shows your plants are using water faster than the nutrients.
  • pH – This is the level of alkaline or acidity of a solution. On most occasions, these readings are taken for water alone, but it is advisable to take readings once your nutrients have been added. While 7.0 is neutral, nutrient solutions are better around 6.5 because nutrients are at their most soluble at this level. You can purchase pH adjustment chemicals which can raise or lower the pH level, and also a digital pH reader so you can do quick readings and adjust as necessary.
  • Solution temperature – Temps should be between 65 – 75 degrees. Depending on your climate, you might need to either insulate your reservoir. It is worth noting, if your nutrient mix is too hot, it can breed harmful bacteria, and it won’t do your plants roots any good. If it is too hot, a reservoir chiller might be needed, but these are expensive components to purchase.

Cause and Effect of Nutrient Burn on Plants?

There is a delicate balancing act of 16 different micronutrients and macronutrients to achieve the best plant growth.  If your plants become exposed to too many of these, they can get nutrient burn. This more often than not happens when fertilizer salts reach high levels (can be measured by EC meter).

In hydroponic systems, it can be difficult to control because all the plants have the same exposure. To make things more difficult; plants can get nutrient burn when your levels are as they should be. This occurs when a plant is stressed by another factor. This can include pests or disease, and the plants can’t make use of the nutrients they are offered.

One of the first signs is brown or dead spots that run along the leaf tips and can be separated from the healthy part of the leaf by a yellow halo. Too much nitrogen can make your plants look over lush, and they are full of foliage, but, any fruits can drop early, and a final sign is shriveling root clusters.

If you are growing under grow lights and your plants are too close to the source, the ends of the leaves can burn which gives a very similar symptom. The fix for this is easy, raise the lights or move the plants further away from the source.

Adding Nutrients to Hydroponic Reservoirs Effectively

Nutrient burn can be fixed, and although the affected parts will remain the same, any new growth will be back to normal. This is a case of flushing the system and then re-establishing the correct amount of nutrients. Old nutrients should be flushed from the system, and then clean water is run through for 24-hours.

Hydroponics Unearthed eBook

Once you have fixed your nutrient burn problem, you need to know how to add nutrients most effectively. Here are a few pointers you can follow that will guide you in maintaining the most optimum nutrient levels for your plants:

  • Mark the highest point the water reaches in your reservoir (don’t forget to measure the number of gallons you add). Check the level daily, and when you need to add to the tank keep a count of the gallons you add.
  • Only top up with pH balanced water, if you add nutrients, you rerun the risk of nutrient burn.
  • When you can see you have replaced 50% of your initial nutrient solution through re-filling. Stop adding water and allow the water level to drop until it is just above the top of your water pump. At this point, you can drain and refill with a new batch of nutrients.

If you have an ebb & flow system, you should take this opportunity to flush your pots to remove salts that might have built up. Carefully drench each pot and plant from the top with clean water and let them drain. Clean this out of your reservoir ready for your next batch.

Always fill your reservoir first and then add your nutrients one at a time. These should never be mixed in concentrated form as it can cause lock-out, and prevent some of the minerals being available.

There are many nutrients on the market, and not all are suitable for each plant type. It is recommended to go for 3-part nutrients. An all in one nutrient mix might be convenient, but it can’t give your plants everything they need for their full potential of growth. These deliver the right nutrients at each stage of your plants growing life.  

What are the Best Hydroponic Reservoir Tips

It doesn’t matter what type of hydroponic system you are using; the nutrient solution is the one thing they all have in common. Here are the best tips to keep the optimum nutrient levels for your plants:

  • If the water from your faucet is chlorinated, fill the reservoir or separate mixing bin and let the water sit for 24-hours so the chlorine can dissipate.
  • Once you have added your nutrients, let them settle for a couple of hours before checking your pH levels. 6.5 is the ideal pH level.
  • The solution needs to be aerated 24/7 to prevent any bacteria building up. This also helps to pass oxygen to the plant roots. An effective aquarium air pump can suffice for this job.
  • One tablespoon of hydrogen peroxide added to your reservoir weekly can help cut down on bacteria and algae growth.

Related Questions

Are hydroponic plants healthy?

This has been a debate for many years. It does depend on the nutrients the plants are being grown in. They can be as nutritious as any soil grown vegetable. Many vitamins are self-made by plants, so these levels don’t vary too much regardless of whether the plant is hydroponically grown or soil grown.

Do hydroponic vegetables need pesticides?

There is no need to use pesticides in hydroponics. Plants grown by this method are less prone to pest attacks. Many growers make use of companion crops, ladybugs and other useful insects as more natural pest control methods to combat any pests which might attack their crops.

Can I use liquid fertilizer in hydroponics?

Many commercial fertilizers only supply plants with potassium, phosphorus and nitrogen. Because no soil is used, there is a lot of other nutrients that need adding to the hydroponics liquid fertilizer to help with plant growth.

Hydroponics Unearthed eBook