Hydroponic Fertilizers, Nutrients, Manures Guide

Hydroponic Fertilizers, Nutrients, and Manures

Today, let us talk about Hydroponic Fertilizers, Nutrients, and Manures.

Hydroponic Nutrients:

As the hydroponic medium will have no soil, the nutrients required by the plants in order to survive should be given directly to their roots. The main thing to take care of here is the delivery of the nutrients in an ideal quantity. And this is not that easy to follow. It is not that easy like dumping the fertilizers into the water present in the system. Plants usually require sixteen elements for their reproduction and healthy growth. Each and every element is taken in a different way by the plants. Few of the elements are taken by the exchange of gas through the pores of the leaf called stomata. Few others are taken by the roots directly. This would become tough when a particular element has become a part of a particular compound which is used by the plant. For example, Nitrogen has to be a part of the molecule of nitrate).

The below three nutrients will be available in the water and air. In order to optimize these nutrients, the Carbon dioxide levels should be high and the water should be oxygenated well. If the carbon dioxide levels are low or not present, then the production would be very less mainly in the indoor growing.

• Carbon – C
• Hydrogen – H
• Oxygen – O

The below three nutrients are the ones which are available in the fertilizers which are considered as main. This main fertilizer is available in the form of the mixture of N-P-K

• Nitrogen – N
• Phosphorus – P
• Potassium – K

Calcium is the element which would be available to the plants in the form of Calcium Nitrate which is another fertilizer used commonly. It is mandatory to use Calcium Nitrate in the system of hydroponics.

• Calcium – Ca

The below two nutrients will be available in the form of Magnesium sulphate i.e., MgSO4.

• Magnesium – Mg
• Sulphur – S

The above listed seven nutrients are very rarely become deficient and these can be negligible as they would be available anyways. The main deficient nutrient will be Iron (Fe). This deficiency can be covered by using iron, which is collected. Molybdenum and Chlorine are also essential. But these would become toxic if used in high levels.

• Copper – Cu
• Zinc – Zn
• Boron – B
• Molybdenum – M0
• Iron – Fe
• Manganese – Mn
• Chlorine – Cl

The symptoms shown by the plants help the farmers or growers to identify which nutrient or element is missing. Each symptom shows a different deficiency.

Nutrients in the form of Salts:

Nutrients will also be present in the form of salts and this will make measuring simple. Salts in the sense, the topic is not about table salts such as sodium chloride. Salt is one of the types of compounds and most of the nutrients will come into the system which is attached to something in the form of salt.

1. When the salts are dissolved in water, the ionic bond which is responsible for holding the atoms together in the form of a molecule by using the charge is broken. Due to this, the salt gets split by leaving the ions which can be made use of the plants.
2. Due to this, the electroconductivity of the solution will change and by our luck, it is very simple to measure the electroconductivity.

These two distinguishing qualities or characteristics of salts will make the measurement of nutrients easier. The amount of salt in a mixture or solutions is equal to the number of nutrients present in the solution or mixture. Hence, we can use electro-conductivity for the measurement of nutrients.

This measurement of nutrients by using an electroconductivity is very much important to run a hydroponic system. But even the electro-conductivity has its limits for the measurement. The electro-conductivity will only calculate the total quantity of salts present in the solution, whereas the ratio of the nutrients to the nutrients present in the hydroponic system cannot be calculated.

Most of the people are in an assumption that all the plants present in the hydroponic system take or get the nutrients at the same rate and it is completely wrong. The nutrient content is taken by the plants depending on the age of the plant and the type of crop. By the time, few nutrients may accumulate in the system, whereas the others will reduce in terms of concentration. This problem can be resolved in two ways.

• Hydroponic growers need to balance the nutrients one after the other which requires usage of a many-part fertilizer and an analysis of water present in the hydroponic system.
• By periodically flushing the system and starting it all over again. This would remove all the fertilizers and water, which are wasted and this method is done every six months, mostly for the crops which are very aggressive. The hydroponic growers who are mostly small and have moderate systems will flush the system and use 3-part hydroponic fertilizers which are affordable.

Read: Vertical Vegetable Gardening Ideas.

Adding nutrients to your Hydroponic system:

If the hydroponic system you are growing is a farm wall one or a system which uses a liquid fertilizer, it is very easy to add the nutrients. You can simply mix the Dyna Gro or any other liquid fertilizer, which is mentioned in the instructions when you just start the hydroponic system and the solution can be replaced with a new mix every time you plant. If the transplantation of plants occurs more often, you can top-off the system with a diluted solution until you again start the system.

In order to add the nutrients to a hydroponic system which is a lathe one, you need to be very precise. Add the nutrients only when the level of electro-conductivity will drop by the target level of electro-conductivity. The targeted electro-conductivity level can be measured by using an electro-conductivity meter and is determined by the ranges which overlap between the crops. The range would be mostly between 1300 to 1500 but you need to find a small range between that to get the electro-conductivity which is targeted.

Using pH to detect nutrient usage:

The other most important thing to be remembered while adding the solution is the regulation of pH. The pH is the one which dictates the nutrients used by plants and the microorganisms present in the hydroponic system. If you are giving the nutrient dose by hands manually, you need to check the pH levels at least two times a day.

Usage of a pH pen is the simplest way to calculate the pH level or the automation of the two processes would help. The hydroponic farmers who have automated the nutrients and pH are found using an automated system for dosing. This auto-dosing system is a computer which consists of pumps and sensors attached to the stock solutions. The sensors which are hooked to the computer system will test the water present in the sump tank for every 10 seconds and will automatically correct it.

 Nutrient Deficiency signs in Hydroponics:

Each of the mineral elements required by the plant has its own set of ‘deficiency signs and symptoms’ and growers can learn to identify many of these. Though most of the symptoms look similar, few will have unique signs and must be observed carefully.

Nitrogen (N): If there is a deficiency of nitrogen, then the plants will be short and the leaves will have a green-yellow colour. This colour is seen mainly in the foliage which is older.

Phosphorus (P): In the plants in which there is a deficiency of phosphorus, the plants would be stunted and will be a colour of dark green. These symptoms will first appear on the leaves which are older and the maturity of the plant gets delayed. The deficiency of phosphorus in a few of the species of plants will be due to the cold temperature which would lead to difficulty in taking this element.

Potassium (K): If there is a deficiency of potassium in the plants, the leaves become yellow in colour with the spots which are dark brown or black in colour. If the deficiency is severe, then the plants will stunt and the foliage will turn yellow in colour and also get curled.

Sulfur: The deficiency of sulfur is not a common one and if there is any deficiency by chance, then the leaves turn yellow in colour and will be seen on the leaves which are grown newly.

Magnesium: The deficiency of magnesium is mostly seen in the tomato cultivations which have the leaves which are old. These leaves will turn yellow in colour and the area of leaves which are in the middle of the veins will be green in colour.

Calcium: If there is a deficiency of calcium, then the leaves which are young will be affected first then the old ones. These young leaves face distortion, get reduced in terms of size with spots on them. There would be inhibition in the development of buds and the tips of the roots die.

Iron: If there is a deficiency of iron, then the yellowing can be seen on between the veins of leaves which actually stay green in colour. This is mostly seen in the leaves which are grown newly or the leaves which are younger.

Chlorine: The deficiency of chlorine will lead the leaves to wilt and then makes the leaves yellow in colour and gradually, they turn into bronze colour. The roots of the plant become stunted and the tips of the roots get thickened.

Manganese: When there is a deficiency of manganese, in the initial stages, the older or younger leaves turn yellow in colour and this completely depends on the type of plant. There would be dry areas developed on the leaves which would eventually make them fall.

Boron: If there is a deficiency of Boron, then the size of the plant decreases and the growth also gets affected. The tips of the roots get swollen and the colour also vanishes. The leaves will gradually get thick and will have spots which are yellow in colour.

Zinc: The deficiency of zinc would lead to shorter plants and there would be a decrease in the size of the leaf and the length of the internode. The edges of the leaf face distortion and there would be yellowing in between the veins of the leaf which would usually be green in colour.

Copper: The deficiency of copper is very rare, but this causes the young leaves to become dark green in color with spots which are dry.

Molybdenum: The leaves which are older will have yellowing in between the veins. The edges of the leaf will have scorching.

Read: Community Garden Benefits.

Hydroponic fertilizers:

The system of hydroponics will require the fertilizers which have been crafted in a careful way in order to mix with the solution of nutrients for the crops. Different crops will be given fertilizers which are formulated in a different way. For example, the tomatoes, which are nutrient hogging will require a fertilizer with a different formula than the lettuce which is reserved.

The fertilizers used in the hydroponic system will be available in the form of liquids and also as granules which are dry. These do have both advantages and disadvantages.

The fertilizers which are available in the liquid form are one-part fertilizers which are complete and can be mixed into water to prepare a nutrient solution. This would be simple, but the disadvantage is the storage and the costs of shipping.

The fertilizers which are in the powdered form are very difficult to mix, but they are easy for the storage and even the cost of shipping will be less. The fertilizers which are available in the form of dry granules are mostly preferred by the farmers and the hydroponic growers who just do hydroponic gardening as a hobby would prefer liquid fertilizers.

Hydroponic fertilizers needed for the system:

The fertilizers which are available in the powdered forms or dry forms will be available in the form of 1-part, many-part mixes.

• The mixes which are one-part will be very simple to mix. The mixing can be done according to the rate present on the bag. These one-part mixes are not suitable to make stock solutions as there would be a chance for the precipitation of the few nutrients with high concentration which makes them solid and not usable.
• The mixes which are multi-part are the ones which most of the hydroponic growers select. These multi-part mixes are very simple to mix and also allow the hydroponic growers to prepare the stock solutions as the compounds which cause problems are kept separately.
• The mixes which are many-part are the ones which are ccost-effectivefor large operations to be carried. There would be eleven fertilizers present. These will be mixed and also stored separately.

Three-part fertilizers:

The common method which is used mostly in order to make a hydroponic system fertilized is by using a three-part fertilizer which is mixed into two stock solutions.

• The mix of N-P-K: This mix is the basic one and consists of the three nutrients which are available in plenty. There would be different formulas of mixing these nutrients for different crops.
• Calcium nitrate, CaNO3: This mix will provide calcium and few more nitrates to the plants present in your hydroponic system. As the calcium does not get mixed with the magnesium sulphate, it gets mixed with the mix of NPK in the stock solutions.
• Magnesium sulfate, MgSO4:  This is also called as Epsom salt and is used as a supplement for the sulfur and magnesium. The mixture and the storage are done by itself.

When the above three parts are used as a stock solution by manually adding or by dosing in an automated way, they would be kept as a stock and the stock A would contain NPK mix and CaNO3 mix whereas the stock B would contain MgSO4 which would adjust the pH levels.

Points to remember while buying hydroponic fertilizers:

Electro-Conductivity levels: These levels refer to the electro conductivity of the water in the solution of the nutrients.

Type of fertilizer: This should be either powdered, granulated or liquid.

Level of pH: The hydroponic fertilizers, you choose should help in buffering the level of pH in the water when applied.

The present stage of growth: Few hydroponic fertilizers are used for the maintenance whereas few are used in the stage of blooming and this completely depends on your choice.

Hydroponic Manures:

The plants present in the hydroponic system will be fed with liquid fertilizers as they do not contain soil in the growth medium. The fertilizers which are used, commercially contain Nitrogen, Phosphorus and potassium. Minerals and Micronutrients such as iron and zinc are not included as they are available abundantly in all types of soil. As there would be no soil, every element essential for the growth of plant should be added to the liquid fertilizer in hydroponics. The fertilizers which are specialized will be very costly, so the hydroponic gardeners will prefer to prepare the liquid fertilizers at home. These will not be dependent on the food production on large-scale, but they work very well when the number of plants is less and growth which is consistent is not that required.

Compost Tea or Worm Tea

• Take a bucket which is about 5 gallons and put one gallon of compost in it or you can also put one pound of worm castings.
• This bucket should be filled with water and should be stirred.
• The mixture should be aerated by using an aquarium air pump.
• Leave the bucket and let it sit for some time by avoiding the direct sunlight.
• This liquid should be poured by using a filter which is disposable so that all the solids would be strained out. The liquid which remains is called the compost or worm tea and can be used as a fertilizer.

Animal and Plant Byproducts

• 1 gallon of water should be added to a bucket.
• Then one and a half teaspoons of fish emulsion should be added to the water along with one and a half teaspoons of an extract of seaweed and one tablespoon of blood meal.
• All these should be stirred and mixed well and can be used as a fertilizer to the hydroponic plants. These ingredients should be used in the same ratio for the large volumes of water too.

Read: Organic Compost Preparation and Methods.

Last Updated: February 15, 2019