How to Mix Nutrient Solution for Hydroponic Plants? A Detailed Guide to Several Common Formulas

Hydroponic plants have many advantages compared with soil-grown plants. Hydroponic plants are of good quality. Since the nutrient solution for flowers is formulated according to the growth needs of the flowers, the flowers produced are large and numerous, with a strong fragrance, vivid colors, and a long blooming period. Hydroponic plants save nutrients, water, and labor. For hydroponic plants, you only need to regularly replenish the nutrient solution for the plants, which is simple to do and saves labor and time. They are clean, free of weeds, and have few pests and diseases. Today, the editor will mainly introduce two common nutrient solution formulas for hydroponic plants.

Nutrient Solution Preparation for Hydroponic Plants

1. Substrate Preparation

The main function of the soilless cultivation substrate is to fix the flowering plants in the container. Currently, the commonly used soilless cultivation substrates in China are:

① Sand grains with a diameter of less than 3 mm.

② Natural gravel, pumice, volcanic rock, etc. with a diameter greater than 3 mm.

③ Vermiculite, a mica-type mineral with good buffering capacity that does not sink in water.

④ Perlite. It works better when mixed with mudstone and sand.

⑤ Peat with good air permeability and strong water-holding capacity, which can be used alone as a substrate or mixed with cinders, etc. In addition, cinders, bricks, charcoal, asbestos, sawdust, fern roots, bark, etc. can all be used as substrates. The substrate should be washed and disinfected before use.

2. Nutrient Solution Preparation

The various elements and their amounts used in preparing nutrient solutions for soilless cultivation of flowers should be determined according to the flower varieties being grown, their different growth stages, and different regions.

Hoagland Nutrient Solution Formula

At present, there are many soilless cultivation nutrient solution formulas in the world. Most publications on soilless cultivation have collected many formulas; for example, Hewitt (1966) collected about 160 formulas. Some formulas have proven to be quite good after decades of use. The Hoagland formula is also the most original one. Many sources say it was discovered by Hoagland himself in 1935, but that is not actually the case. It was published in 1933 after he and his research partners conducted a large number of comparative experiments. This is the most original classic formula that is still in use today.

1. Nutrient solution formula: calcium nitrate 945 mg/L, potassium nitrate 607 mg/L, ammonium phosphate 115 mg/L, magnesium sulfate 493 mg/L, iron salt solution 2.5 ml/L, trace elements 5 ml/L, pH=6.0.

2. Modified Hoagland formula: calcium nitrate tetrahydrate 945 mg/L, potassium nitrate 506 mg/L, ammonium nitrate 80 mg/L, potassium dihydrogen phosphate 136 mg/L, magnesium sulfate 493 mg/L, iron salt solution 2.5 ml, trace element solution 5 ml, pH=6.0.

3. Iron salt solution: ferrous sulfate heptahydrate 2.78 g, disodium edetate 3.73 g, distilled water 500 ml, pH=5.5.

4. Trace element solution: potassium iodide 0.83 mg/L, boric acid: 6.2 mg/L, manganese sulfate: 22.3 mg/L, zinc sulfate: 8.6 mg/L, sodium molybdate: 0.25 mg/L, copper sulfate: 0.025 mg/L, cobalt chloride: 0.025 mg/L.

5. Precautions

① If used as a compound fertilizer, it can be prepared with natural water, omitting the trace element solution. If used as a soilless cultivation nutrient solution, it needs to be prepared with artificial soft water, such as distilled water, and the trace element solution must be added.

② The above nutrient solution is often prepared at 10 times or 20 times concentration, and diluted when used. Note that the pH should be adjusted before use (different plants have different pH requirements, so it can be adjusted appropriately). In soilless cultivation, for crops to maintain normal growth and development, they must contain 13 essential elements, and all of them must be in a form that plants can absorb, that is, in an ion-dissociated state. In addition, the ratio between ions must also be appropriate. Only when the nutrient solution meets the above conditions is it possible for crops to develop well and achieve high yields. There are now hundreds of nutrient solution formulas published in the world, among which Hoagland solution is the most famous and is widely used by nutrient solution experimenters and growers in various countries.

Morard Nutrient Solution Formula (the world's most famous nutrient solution formula, and also the most commonly used nutrient solution formula)

Solution A: calcium nitrate 125 g, ferrous sulfate 12 g. Add the above to 1 kg of water.

Solution B: magnesium sulfate 37 g; ammonium dihydrogen phosphate 28 g; potassium nitrate 41 g; boric acid 0.6 g; manganese sulfate 0.4 g; copper sulfate 0.004 g; zinc sulfate 0.004 g. Add the above to 1 kg of water.

1. Preparation Process of the Nutrient Solution

① Weigh each fertilizer separately and place them in a clean container or plastic film bag, or on a plastic film bag spread flat on the ground, for later use.

② When mixing and dissolving fertilizers, strictly pay attention to the order. Ca2+ must be kept separate from SO42- and PO43-, that is, calcium nitrate cannot be mixed with several fertilizers other than potassium nitrate, such as sulfate types like magnesium sulfate, or ammonium dihydrogen phosphate, so as to avoid calcium precipitation.

③ For the dissolution order of fertilizers in tank A, first use warm water to dissolve ferrous sulfate, then dissolve calcium nitrate, adding water while stirring until evenly dissolved; for tank B, first dissolve magnesium sulfate, then add ammonium dihydrogen phosphate and potassium nitrate in sequence, add water and stir until completely dissolved, dissolve boric acid in warm water and add it, then add the remaining trace element fertilizers separately. After both liquid tanks A and B are stirred evenly separately, set them aside for use.

④ When using the nutrient solution, first take 10 ml of the mother liquor from tank A and dissolve it in 1 kg of water, then add the mother liquor from tank B to this 1 kg of water, and it is ready for use.

2. Adjusting the pH of the Nutrient Solution

The pH of the nutrient solution directly affects the state, transformation, and availability of nutrients in the nutrient solution. For example, phosphates are prone to precipitation under alkaline conditions, which affects their utilization; manganese, iron, etc. in alkaline solutions will also cause deficiency symptoms due to reduced solubility. Therefore, adjusting the pH (that is, the pH value) of the nutrient solution cannot be ignored.

The nutrient solution is generally prepared with well water or tap water. If the pH value of the water source is neutral or slightly alkaline, the pH value of the prepared nutrient solution will be similar to that of the water source; if it does not match, it needs to be adjusted. When adjusting the pH value, first dilute strong acids and strong alkalis with water. When the nutrient solution is too alkaline, phosphoric acid or sulfuric acid is mostly used to neutralize it; when it is too acidic, sodium hydroxide is used to neutralize it. Then add it drop by drop into the nutrient solution while continuously measuring with pH test paper until it reaches neutral. Generally, pH reaching 7 is the verification standard!

Precautions for Hydroponic Plants

1. If tap water is used when preparing the nutrient solution, the tap water must be treated, because tap water mostly contains chlorides and sulfides, which are harmful to plants, and bicarbonate can also hinder the roots' absorption of iron. Therefore, when using tap water to prepare nutrient solution, a small amount of sodium edetate or humate compounds should be added to treat the chlorides and sulfides in the water. If the substrate used in hydroponic plant technology is peat, the above disadvantages can be eliminated. If the quality of groundwater is poor, unpolluted river water or lake water can be used for preparation.

2. If no nutrient solution is used and only ordinary water culture is used, it is also fine, but the growth will be somewhat worse and slower. Usually, the cultivation water in the pot should be replaced once every one or two months. Tap water can be used, but be sure to let the tap water sit for a period of time before use, so as to keep the root temperature stable.

3. Most hydroponic plants are shade-loving and neutral flowers suitable for indoor cultivation, and they have their own requirements for light. Shade-loving flowers such as ferns, Orchidaceae, and Araceae plants should be moderately shaded; medium-sized flowers such as Monstera deliciosa, Schefflera octophylla, and poinsettia are not strict about light intensity and usually like sufficient sunlight, and can also grow normally under shade. Ensuring the temperature for normal flower growth is very important. Flower roots grow better within the range of 15-30 degrees.

4. Attention should be paid to identifying the root color of the flowers to determine whether they are growing well. When light, temperature, and nutrient solution concentration are appropriate, the whole root or the root tip is white. Please note that excessive nutrient solution is strictly prohibited, and shortening the time interval for adding nutrient solution is strictly prohibited.

5. During the growth of hydroponic plants, if water droplets are found seeping from the leaf tips, the water level should be appropriately lowered so that more roots are exposed to the air, reducing the proportion of soaking in water, which is beneficial for oxygen absorption.

Cultivation Methods for Hydroponic Plants_How to Prepare Nutrient Solution for Hydroponic Plants

Scientific research shows that plants can absorb harmful gases and attach them to the leaf surface, especially the root system of hydroponic plants, whose adsorption capacity is stronger. They can incorporate harmful gases and dust into their metabolic process and remove their toxicity during substance transformation. So today let us take a look at the cultivation methods for hydroponic plants and how to prepare the nutrient solution.


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Proper ventilation for hydroponic plant cultivation methods:
      The condition of hydroponic plants is directly related to the oxygen content in the water, and the amount of oxygen in the water is related to the activities of indoor people and the quality of ventilation. When indoor ventilation is poor and people are frequently active, the oxygen content in the water decreases rapidly, which will affect the growth of hydroponic flowers, while maintaining good indoor ventilation can increase the oxygen content in the water.

Spray water to wash leaves:
      Hydroponic plants, especially indoor hydroponic foliage plants, mostly prefer higher air humidity. If the indoor air is too dry, it will cause leaf tip burn or leaf edge burn. This affects the ornamental value of the flowers. Therefore, water should often be sprayed on the plants to increase air humidity, which is beneficial to the normal growth of the flowers.
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Maintain hygiene:
      Hydroponic plants use inorganic nutrition, and organic matter entering the water is most taboo, and organic fertilizers must not be used. Therefore, always keeping hydroponic flowers clean and hygienic is a key measure to ensure their good growth. So usually do not put food or organic fertilizers into hydroponic flowers. Do not casually put your hands into the water either, so as to ensure that the water quality does not deteriorate or become polluted, keeping it clean and hygienic, and ensuring flower growth.

Precautions:
      First, note that the roots of the plants cannot be completely soaked in the water. The root system needs 5-10 cm exposed to the air. If the root system is completely soaked in water, the roots cannot absorb oxygen and will die from lack of oxygen. The roots exposed to the air can supplement oxygen. Second, change the water frequently to maintain dissolved nutrients in the water. Third, the nutrient solution components for hydroponics must be properly proportioned, and the concentration must not be too high!
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How to Prepare Nutrient Solution for Hydroponic Plants
      For nutrient solution for hydroponic plants, it is generally fine for everyone to use the dedicated hydroponic nutrient solution sold on the market. Prepare the appropriate concentration according to the instructions, such as diluting 400 times or 1000 times. Do not get the ratio wrong. When preparing, let the tap water sit for two hours to half a day, wait until its temperature is close to room temperature and the chlorine in the water has volatilized completely, then add the concentrated nutrient solution in proportion, and it becomes a nutrient solution that can be used to grow hydroponic plants.

      Here, the editor introduces a widely used nutrient solution formula. The world's most famous Morard nutrient solution formula: Solution A: calcium nitrate 125 g, ferrous sulfate 12 g. Add the above to 1 kg of water. Solution B: magnesium sulfate 37 g, ammonium dihydrogen phosphate 28 g, potassium nitrate 41 g, boric acid 0.6 g, manganese sulfate 0.4 g, copper sulfate 0.004 g, zinc sulfate 0.004 g. Add the above to 1 kg of water. The simplest method is to use bottled mineral water and add a few elements.
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Editor's Summary
      Because hydroponic plants use this soilless cultivation technology, they have won the favor of flower consumers at home and abroad with advantages such as being clean and hygienic, elegant in style, highly ornamental, and environmentally friendly and pollution-free. Today the editor's introduction to hydroponic plant cultivation methods and how to prepare the nutrient solution ends here. Thank you all for reading.

Application of Nutrient Solution for Hydroponic Flowers