DIY Hydroponic Nutrients

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By Alex Harris

In a hydroponic system getting the nutrient solution correct is vital for the health of the plants. After all, you’re replacing the plant’s soil with water. Remember, when a plant is in healthy soil there’s a mixture of nutrients and micronutrients for it to tap into.

In any hydroponics store there will be loads of readymade products to assist you with finding the correct nutritional balance for your plants. While these products do work, they also come with a pretty hefty price tag.

Luckily, many growers have faced the same issues and have created their own homemade hydroponic nutrients. For newer horticulturists, this might seem like an immense undertaking, but making your own hydroponic nutrients is actually fairly easy.

Before we get into how to make your own DIY hydroponic nutrients, let’s focus on the equipment you will need.

Related: Best Hydroponic Nutrients

Items You Will Need To Make Your Own Hydroponic Nutrients

It shouldn’t come as a surprise, but everything your plant needs can be created from an organic source. We don’t mean that the supplies have to be organically grown, just natural.

For equipment you will want to source an accurate scale to make sure that you’re measuring out the correct amounts. The next item will be a measuring jug and cups to make sure you are adding in the correct volumes of ingredients.

As you will be mixing the substances together, you will want to have access to a bucket, tub, or any waterproof container. You’ll also want a stirring device, which can be a spoon or automatic mixer.

And finally, you will need a pH testing kit, as well as a pH adjustment kit to ensure that the correct pH is achieved in the nutrient solution.

The last piece of equipment you’ll need is an electrical conductivity (EC) meter, which you can use to measure the total dissolved nutrients in the solution.

While you can wear gloves if you prefer, it’s not needed.

Here’s a quick breakdown of the elements you’re most likely need when formulating your hydroponics:

  • Measuring scale
  • Measuring jug and cup
  • Bucket or tub
  • Mixing spoon or mixer
  • pH testing kit
  • pH adjustment kit
  • EC meter
  • And gloves (optional)

Now that you know what you’ll need, let’s focus on the essential elements your nutrient solution will need.

Essential Nutrient Elements For A DIY Hydroponic Solution

There are two categories of elements that plants require, macronutrients and micronutrients.

As their names suggest, macronutrients are the elements plants need more of while micronutrients are only needed in trace amounts. Even though the latter is only needed in tiny amounts, they are still crucial for plant growth and development.

There are 13 essential elements that plants require for growth. A part of these 13 elements are the three main macronutrients, often referred to as the N-P-K ratio. The NPK ratio will be familiar to most gardeners who often look at fertilizers on the shelf at the garden center.

The N stands for nitrogen, P is phosphorus, and K is potassium. When reviewing a fertilizer’s NPK ratio, these numbers are percentage measurements. This being said, there are still a number of other macronutrients, such as:

  • Calcium (Ca)
  • Magnesium (Mg)
  • And Sulfur (S)

On the micronutrient list are:

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

While plants will also require carbon (C), hydrogen (H), and oxygen (O), these will be absorbed via the intake of air and water.

If you are wondering how to source these elements for your own DIY mixture, you can purchase certain fertilizer salts from your local garden center, drug store, or even local grocery store.

An element you can pick up at most grocery stores is epsom salts, otherwise known as magnesium sulfate because these salts contain magnesium and sulfur. For anyone who owns a lawn, the magnesium element will be familiar. Magnesium is a component of chlorophyll and is responsible for distributing phosphorus throughout the plant.

In the case of grass, it makes it greener. On the other hand, sulfur is responsible for the production of energy for the plant.

Potassium sulfate provides two elements to your plants, which are potassium and sulfur. Potassium is also required to produce energy in your plant.

The next salt you can purchase is potassium nitrate. Nitrogen is used in the plant to build stems, leaves, and plant cells. It’s one of the main elements in store-bought fertilizers.

Superphosphate is a combination of phosphorus and calcium. In the early stages of a plant’s life, increasing the levels of phosphorus can improve the yields later on, while the calcium will help with root development.

And for the other elements you can purchase the salts off the shelf.

For a more organic approach there are simple kitchen scraps you can also use.

Egg shells are an amazing source of extra calcium. But you need to break them down before adding them into the mixture, because otherwise the calcium will take ages to become bio-available.

The first step is to crush them up finely with a pestle and mortar. Once you’re happy with consistency, add the egg shell powder to water with a few drops of diluted hydrochloric acid, making sure to wear gloves. Leave the solution for 24 hours. Your eggshell mixture can now be added to your fertilizer.

Bananas are also a great natural additive for fertilizers as they contain the most potassium out of all-natural products. Potassium helps plants to take up sugars and starches, as well as carbs. These elements help with building the structures like stems and leaves.

To extract this potassium for hydroponics you will need to create banana tea. This can be done by boiling a quarter gallon of water, throwing in three to four banana peels, and adding in some molasses or sugar (a tablespoon will do). When the mixture cools down enough to touch, remove the peels and use as desired.

Another useful byproduct is coffee grounds. While you won’t be using the grounds directly, you will be adding them to a compost bin, as the grounds are slightly acidic and acetic bacteria will develop, which contain around 2% nitrogen.

Brewer’s yeast is also a great fertilizer but just be warned it is not the same as baking yeast. When dissolved into water, it turns into a potassium and phosphorus rich natural fertilizer.

Another ingredient available to those close to the coast is seaweed. Seaweed is jam packed with vitamins and minerals, all useful for plants.

And the last homemade fertilizer to remember is bean tea. Beans and lentils contain auxins. These compounds help with root and leaf growth. To create this organically, soak your beans in water until well hydrated then grind into a paste.

Strain the paste and use the auxin rich water.

Now before you start to mix your nutrients to build your own fertilizer, you will need to learn how to diagnose problems, so you know what ratios to formulate to fix them.

Diagnosing Plant Problems

When tweaking your formulas for your hydroponic system you need to do it slowly as adding too much to your fertilizer can kill your entire crop.

Also, note these general/common symptoms in plants with nutrient deficiencies.

A lack of nitrogen will produce a plant that is stunted in size with large roots. The leaves will also be smaller and light in color.

If the plant has stunted growth but has dark, dull, leaves, it is lacking phosphorus. Another symptom is unusually hard stems with poor roots with little to no branching.

When older leaves on a plant start to yellow and curl, with newer leaves dropping, you might have a lack of potassium. The flowers on the plants will also be lackluster and the stems will be soft.

Calcium deficiency is shown when roots are underdeveloped and the leaf edges are curled.

And the last obvious sign of nutrient deficiency is a lack of manganese, which results in weak growth and poor blooming.

Now, let’s get to some recipes for the best DIY hydroponic fertilizers.

DIY Hydroponic Fertilizer Recipes

Before adding a DIY fertilizer to your system, conduct pH and EC tests. The results will help you adjust before subjecting your plants to unnecessary stress.

An incredibly simple fertilizer to gather is kelp. Place it into a cheesecloth and allow it to soak in a five gallon bucket, placed in the sun, for 5 days. When ready, add 5 teaspoons of epsom salts. And you’re done.

You can add some additional fertilizer salts to address certain issues, but the mixture should be great for general use.

If you want a proper all-round fertilizer you can fill a container with the appropriate amount of warm water – use a five gallon bucket.

Test the water’s pH and EC. Once happy, add in the salts in the suggested quantities. Allow the water to cool and test the pH and EC levels again.

Once you’re happy, you’re ready to go.

If you change your mind and want to buy a fertilizer, check out our buying guide: Best Hydroponic Fertilizer

Now You Know How To Make Your Own DIY Hydroponic Nutrients

And just like that, you’re ready to create your own bespoke nutrients for your hydroponic system.

As long as you monitor your plants and adjust your solution to meet their needs, your plants should grow up strong and healthy.