Making Hydroponic Nutrient Solution at Home

Hydroponics offers a soil-free method for growing vibrant, healthy plants by supplying their nutritional needs directly through an optimized water-based solution. Creating your own hydroponic nutrient mix at home gives you greater control over the ingredients and ratios, while also saving money compared to buying pre-made solutions. With just a few simple components readily available at gardening stores or online, you can craft a customized hydroponic formula designed specifically for your plants and system.

In this comprehensive guide, you’ll learn the key principles behind formulating hydroponic nutrient solutions, including understanding essential macro and micronutrients. We’ll explain how to obtain pure synthesised salts for primary nutrients like nitrogen, phosphorus, and potassium and combine them in evidence-based proportions. You’ll also discover how to integrate vital secondary nutrients and trace minerals to address the micro-nutritional requirements of your hydroponic plants.

Can You Grow Hydroponics Without Nutrient Solutions?

While nutrient solutions form the core of most hydroponic systems, some alternative methods allow growing plants without a traditional hydroponic nutrient mix. However, these techniques have limitations and may not work for all plants or growing situations.

The most common approach is using organic hydroponics. Instead of mineral salts, organic hydroponics relies on organic materials like compost, vermicompost, coco coir, worm castings, and guano to provide nutrients. The organic materials break down slowly in water, releasing plant-available nutrients over time. This can support healthy plant growth but typically at a slower pace than standard hydroponic nutrient solutions.

Another option is aquaponics, which combines hydroponics with aquaculture in a symbiotic system. Fish waste and byproducts provide organic nutrients for plants grown hydroponically. However, balanced nutrients rely on a healthy, thriving fish population supported by the system.

Passive hydroponics is possible for some plants like lettuce, herbs, and leafy greens. By using a growing media high in cation exchange capacity like expanded clay pebbles, the growing medium can retain and release some essential minerals naturally present in water over time. However, this approach is not reliable for all plant types.

While growing hydroponically without traditional nutrient solutions is possible, it may not be optimal. Plants typically derive the highest benefit from controlled mineral salt solutions tailored to their nutritional needs. But alternative methods like organic hydroponics can allow growing with natural inputs for those seeking to avoid synthetic chemical nutrients.

 

What Nutrients Are Used In Hydroponics?

Hydroponic systems provide plants with everything they need to thrive in a soilless solution. But what exactly are the ingredients that make up these specialized hydroponic nutrient solutions? By understanding the specific mineral elements plants require, you can learn to mix customized hydroponic nutrients tailored to your plants’ needs.

In this section, we’ll provide an overview of the key macro and micronutrients used in hydroponics. We’ll explain what each major and minor nutrient contributes to plant growth and development.

Macronutrients

Macronutrients are the primary nutrients required in relatively large amounts to sustain plant growth and development. These essential elements are taken up from hydroponic nutrient solutions in the following proportions:

1. Nitrogen. The most important nutrient in hydroponics. It drives vegetative growth and leafy green development. Nitrogen is mobile in plants, and a deficiency quickly shows in chlorosis and stunted growth. Common nitrogen sources in hydroponics include calcium nitrate, potassium nitrate, and ammonium nitrate.
2. Phosphorus. Supports root growth, flowering, and fruit production. It aids in energy transfer as a component of ATP and phospholipids in cell membranes. Deficiencies appear as reduced growth and purpling of older leaves. Monopotassium phosphate and phosphoric acid provide soluble phosphorus in hydroponics.
3. Potassium. Regulates water movement in plants, enzyme activation, and nutrient transportation. It also increases disease resistance. Potassium deficiency causes marginal leaf burn, necrosis, and high susceptibility to stresses. Potassium nitrate, potassium sulfate, and monopotassium phosphate are standard potassium fertilizers.
4. Calcium. Strengthens cell walls, improves stress tolerance, and regulates enzymatic and hormonal processes. Common deficiency signs are stunted roots and tip burn on leaves. Calcium nitrate is the predominant calcium source used in hydroponic fertilizer formulas.
5. Sulfur. It is present in many proteins and vitamins in plants. It helps with enzyme activation, protein synthesis, and nitrogen metabolism. Deficiencies present as overall chlorosis and slow growth. Sulfur is available in sulfates of magnesium, potassium, and manganese.
6. Magnesium. Aids enzyme reactions, PSB production, and stability of cell membranes and ribosomes. Deficiencies result in interveinal chlorosis and reddish hues. Epsom salts (magnesium sulfate), magnesium nitrate, and magnesium chelates provide magnesium.

Micronutrients

While macronutrients are required in relatively large quantities, micronutrients or trace minerals are just as essential for plant growth and health but are only needed in very small amounts. The key micronutrients utilized in hydroponics include:

1. Zinc. Important for enzyme and chlorophyll formation, as well as metabolism of carbohydrates and proteins. Deficiencies present as smaller leaves and interveinal chlorosis. Zinc sulfate and chelates prevent deficiencies in hydroponic systems.
2. Copper. Assists in photosynthesis, respiration, and reproductive growth. Deficiency signs are rare but include wilting, distortion, and chlorosis. Copper sulfate and copper chelates provide bioavailable copper.
3. Boron. Plays a role in cell wall and membrane structure, calcium uptake, and hormone movement. Deficiencies result in brittle leaves, bud death, and malformed growth. Soluble borates like boric acid and sodium borate supply boron.
4. Molybdenum. It is essential for nitrogen fixation and nitrate assimilation. Deficiencies are uncommon but cause marginal yellowing of leaves. Sodium molybdate and ammonium molybdate are sources for hydroponics.
5. Iron. It aids in chlorophyll synthesis and is essential for photosynthesis. Deficiencies present as interveinal chlorosis. Iron chelates are commonly used in hydroponics to keep iron soluble and prevent deficiencies.
6. Manganese. Involved in enzyme activation, metabolism, and photosynthetic oxygen production. Deficiency symptoms include interveinal chlorosis similar to iron. Manganese sulfate, chelates, and manganese nitrate are common sources.

Advantages of Homemade Hydroponic Nutrient Solutions

• Cost Savings. Purchasing individual dry nutrient salts and acids in bulk quantities can significantly reduce the costs compared to buying pre-mixed liquid nutrients. While premade formulas are convenient, the manufacturer markup can be substantial. Mixing your own allows much more flexibility to find the most affordable sources for each individual component. With a small initial investment in materials, homemade nutrient solutions can drastically cut the ongoing costs of hydroponic gardening.
• Customization. Pre-blended hydroponic fertilizers are designed for general use, while mixing your own allows you to customize and tweak formulas tailored to your specific plants and system. You can adjust nitrogen, phosphorus, and potassium ratios to optimize growth for leafy greens versus fruiting plants. The concentrations can be modified for seedlings versus mature plants. Adding more or less of certain elements like magnesium or calcium is easier with homemade solutions. It also allows modifying EC, pH and other parameters as needed over time rather than being stuck with generalized off-the-shelf products.
• Ingredient Quality. Buying laboratory or agricultural grade nutrient salts from reputable suppliers gives you greater control over purity and quality. Some commercial nutrient brands use lower purity ingredients or fillers to reduce costs. With homemade nutrients, you know exactly what goes into your formula. High purity salts dissolve cleanly and give you accuracy in developing optimized solutions.
• Concentration Control. Pre-mixed fertilizers have a fixed concentration, while homemade allows you to mix concentrates tailored to your specific reservoir size, plant types, and growth phases. For small hydroponic systems, buying gallons of premade dilute nutrients is unnecessary and wasteful. Concentrated solutions also allow flexibility in diluting to lower concentrations for seedlings or less demanding crops.
• Enhanced Learning. Creating your own hydroponic nutrients from scratch provides an invaluable educational experience. You gain first-hand understanding of which mineral elements are essential for plants and how to provide them in optimal ratios. Following customized nutrient recipes teaches you how to vary concentrations based on plant needs. The experience allows growers to become experts at plant nutrition and troubleshooting deficiencies.
• Avoidance of Excess Additives. Some premade hydroponic nutrient lines contain unnecessary additives like excessive surfactants, dyes, emulsifiers and preservatives. Formulating your own solutions allows avoiding these extras that can potentially cause issues in some systems. It gives you full control over limiting additives to only those that are beneficial.
• Increased Food Safety. With homemade nutrients made from high purity salts and clean water along with good hygiene, you can ensure your hydroponic system stays free of contaminants. This allows production of ultra-clean fruits, vegetables, and herbs, especially important for those with edible gardens.
• Reliable Supply. Once you know how to assemble your own proven hydroponic nutrient mixes, you don’t have to worry about store shelves being out of your favorite brand. The raw ingredients are easily sourced online or at most hydroponic shops. You can always have the materials to make your customized formulas.

Disadvantages of DIY Hydroponic Nutrient Solutions

• Learning curve. Creating your own customized hydroponic nutrient formulations requires dedicating time to research and gain knowledge. Growing information is available online and in books, but determining optimal recipes takes trial and error. Learning which elements are essential and in which ratios takes self-education well beyond basic plant nutrition. Compared to the simplicity of purchased pre-mixed nutrients, DIY solutions involve a more serious commitment to learn the details of hydroponic nutrition.
• Finding quality ingredients. Sourcing high purity grade nutrient salts or compounds for hydroponic formulas takes some legwork. Local hydroponic shops may have limited selection, especially for micronutrients. While agricultural suppliers provide certain salts in bulk, trace elements must be found elsewhere. Not all online vendors sell ingredients tested for hydroponic suitability, and quality can vary. Finding reputable suppliers worldwide providing the range of salts and chelates in small quantities requires research.
• Calculating proper ratios. Mixing multiple mineral salt ingredients together in the ideal proportions for your crop is exacting work. Following published recipes may not meet your specific needs. Optimizing primary macronutrients along with the full spectrum of micronutrients requires precision weighing or measuring on a molar basis. Even small calculation errors when combining multiple components into concentrated stock solutions can result in improper nutrient ratios once diluted.
• Additional equipment needed. While premade nutrients just need dilution and application, mixing DIY solutions requires having the proper equipment and labware. You’ll need an accurate gram scale, measuring containers, something to stir and dissolve salts, storage vessels, protective equipment like gloves and goggles, and perhaps a vent hood depending on ingredients used. While affordable, these supplies represent an upfront cost not associated with off-the-shelf fertilizers.
• Lack of additives. Premade hydroponic nutrients contain proprietary blends of supplements like root boosters, vitamins, penetrants, pH buffers etc. Formulating your own base nutrients alone will lack these additional components that provide potential benefits. You need to know which additives are useful, source them, and properly integrate them into your custom recipes.
• No manufacturer support. There is no hotline or expert technical advisors to consult as you would have with a commercial nutrient brand. It’s up to you to troubleshoot any issues with plant performance that may arise from your homemade formulas through trial and error. Access to experienced hydroponic growers can help provide guidance.
• Time investment for mixing. While cost-effective in the long run, assembling DIY nutrients takes active effort compared to diluting premade concentrated liquids. Working carefully to measure and combine each component, then stirring to fully dissolve salts takes hands-on labor. This process must then be repeated each time a new batch of nutrients is required. The time requirements should be considered.
• Potential handling hazards. Some concentrated mineral salts, acids, and complexed micronutrients can pose health hazards or damage equipment if mixed haphazardly without safeguards. Using protective equipment and proper procedures is critical when using pure chemical ingredients. Handling concentrated solutions also requires added precautions.

Making Hydroponic Solution at Home

Now that we’ve covered the essential nutrients plants need and the benefits of homemade solutions, let’s walk through the process of actually formulating and mixing your own hydroponic nutrient recipe from scratch.

 

Buy the nutrients

Research and select reputable suppliers of laboratory or agricultural grade nutrient salts specifically intended for hydroponic use. Lower grade technical salts may contain excessive contaminants. For major macronutrients, purchase individual salts like calcium nitrate, potassium nitrate, monopotassium phosphate etc. based on your preferred recipe.

Micronutrients like iron, manganese, zinc and others typically come pre-mixed in concentrated chelated forms for stability and availability. Only buy enough to mix a month’s worth of stock solution to ensure freshness. Check expiration dates if purchasing large quantities. Ensure you have all necessary macro and micronutrient components accounted for before mixing to prevent imbalances.

Use clean water

Use purified water like reverse osmosis, deionized or distilled water free of contaminants to begin mixing your hydroponic nutrients. Hard water high in minerals can negatively interact with nutrients, causing precipitation or availability issues.

Test water quality beforehand if purity is uncertain. Problematic ions like sodium and chloride should be near zero for mixing nutrients. Always start with fresh, unstored water. Allowing water to sit can cause chemical interactions, altering its properties.

Mix the salts with water

When mixing the salts with water, add each dry or liquid nutrient source one at a time according to your selected recipe into a mixing container, stirring well after each addition. Use an accurate gram scale and clean tools to carefully measure powders to avoid overdosing certain elements. Mix in warm but not hot water to increase dissolution rate of certain salts as needed, then allow solution to cool before proceeding.

Ensure each nutrient is fully dissolved before adding the next to prevent precipitates from forming that can clog irrigation. Go slowly and be patient – some salts take time to dissolve fully, even with agitation. Proceeding too quickly can impact results.

Add micronutrients

Introduce pre-mixed micronutrient solutions like iron chelate or zinc supplement after fully dissolving all the major macronutrients according to your proportions. Mix thoroughly to distribute trace elements evenly throughout the solution. Micronutrients are only required in small amounts, so uniform mixing prevents deficiencies from uneven concentrations.

Adjust the pH level

After initial mixing, test your hydroponic nutrient solution’s pH and adjust up or down as needed into the optimal range for your specific crops using pH adjusting products. Most plants grow best within a pH range of 5.5 to 6.5 for proper nutrient availability.

However, some crops have slightly different ideal pH levels. Keeping the nutrient solution in the correct pH zone prevents issues with nutrient locks outs and disorders related to pH fluctuations.

Adjust EC level

Once your nutrients are blended and pH adjusted, measure the electrical conductivity (EC) using a meter and modify if needed to achieve your target EC. For most hydroponic plants, an EC between 1.0 and 2.5 mS/cm is recommended, depending on the crop and growth stage.

Seedlings and greens prefer lower EC solutions, while fruiting plants need higher strengths. Compare EC against published ranges for your species. Dilute or concentrate as required to reach optimal EC.

FAQ

How much nutrient solution does a hydroponic system need?

The amount of nutrient solution required depends on the size of your hydroponic system. As a general guideline, you need approximately 2-5 gallons of nutrient solution per square foot of growing area. For smaller systems like a tabletop hydroponic garden, you may only need a few gallons. Larger systems with multiple grow beds will require significantly more. Monitor the solution level and top off as needed to maintain the recommended depth in your system's reservoir.

How often to add nutrients to hydroponic systems?

Most hydroponic nutrients are designed to be effective for 1–2 weeks before needing replenishment. Check the concentration weekly with an EC/TDS meter. When the nutrients drop below the recommended PPM/EC, it's time to change out the reservoir and mix a fresh batch of nutrients. How quickly nutrients deplete depends on factors like plant size, temperature, and water purity. In general, replenish the nutrients in your hydroponic system every 1–2 weeks.

How to keep nutrients in solution?

There are a few ways to help keep hydroponic nutrients dissolved and prevent precipitation/settling:

• Mix your nutrients in reverse osmosis or demineralized water, which lacks minerals that could react.
• Use formulated hydroponic nutrient blends rather than mixing single salts.
• Agitate your reservoir daily to keep nutrients suspended.
• Use a circulation pump in the reservoir to keep the solution moving.
• Check and adjust pH after mixing nutrients to prevent nutrients falling out of solution.
• Make sure any water added for topping off has been dechlorinated.

What nutrient ratio is best for leafy greens vs fruiting plants in hydroponics?

Leafy greens like lettuce, spinach, kale, etc. do best with higher levels of nitrogen, while fruiting vegetables and herbs need more phosphorus and potassium. A ratio of nitrogen-phosphorus-potassium (N-P-K) around 14-16-17 works well for leafy greens. For fruiting plants, a ratio around 8-15-36 provides better nutrition. Tomatoes in hydroponics thrive around 8-16-32 NPK.

How can I lower the PPM/EC if my nutrient solution gets too concentrated?

If your PPM or EC rises above the recommended range for your crop, you can lower it by:

• Doing a reservoir change and mixing a new batch of nutrients at the proper strength.
• Incrementally diluting the reservoir with additional plain water over time.
• Removing some solution and replacing it with plain water to rapidly decrease PPM/EC.
• Adding a nutrient designed for PPM lowering like ZeroTol.

What tools do I need to monitor and adjust hydroponic nutrients?

The essential tools for hydroponic nutrient management are:

• EC/TDS meter - Measures electrical conductivity or total dissolved solids to monitor overall nutrient strength.
• pH meter - Checks pH which affects nutrient availability.
• PPM/EC target charts - To know ideal values for each crop.
• pH adjustment solutions - Such as pH Up/Down for correcting reservoir water.
• Nutrient concentrates - For mixing nutrient solutions to desired strength.