Can Hydroponics Be Organic?

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By Chris Lipsey

Most hydroponics systems are not organic. Hydroponic gardening involves growing plants without soil, which is the main source of nutrients in a natural setting.

Hydroponic agriculture requires the use of mineral nutrients to keep the plants growing. A nutrient mixture containing the optimal ratio of minerals is added to the water reservoir.

While it is possible to find organic nutrient solutions, most products are made with refined minerals.

The lack of organic plant food options makes it difficult to set up an organic hydroponic system. Yet, hydroponics can be organic. Here’s what you should know.

Also read: Are Hydroponic Vegetables Healthy?

What Is Organic Gardening?

The National Organic Program (NOP) decides what is considered organic in the United States. The NOP is the federal program responsible for setting and enforcing the USDA’s standards for organically grown agricultural products.

what is organic gardening

The NOP also works with third-party organizations to certify organic farming practices and organic growers. However, the NOP is not the only group that sets standards for organic production.

The National Organic Standards Board (NOSB) helps set the USDA organic standards. The NOSB is comprised of public volunteers but operates as an advisory board of the USDA.

The NOP and the NOSB don’t always agree. In 2010, the NOSB recommended that hydroponics businesses should be prohibited from receiving organic certification. The NOP disagreed with the recommendation but failed to clarify their position for several years.

In 2018, the USDA Agricultural Marketing Service (AMS), which manages the NOP, announced that hydroponic producers can receive organic certification.

What Are the Standards for Organic Certification?

According to the USDA, organic agriculture production must meet the following requirements to gain the organic label:

  • Growers cannot use genetic engineering
  • The growing operations must use organic seeds
  • Only organic products can be used to control pests and diseases
  • The land must have no prohibited substances for at least three years
  • Crop nutrients must be managed through natural cultivation practices

The last requirement is the one that most directly impacts whether hydroponic growing is considered organic. The nutrients need to be supplied using natural methods. However, the USDA allows growers to supplement with organic crop waste materials and allowed synthetic materials.

The nutrient solutions used by most hydroponic growers are not considered organic. They include synthetic materials that are not permitted by the NOP.

Can You Use Organic Hydroponic Nutrient Solution?

Commercial organic hydroponic nutrients are available. Growers can also create homemade organic nutrient mixes.

Commercial nutrient solutions are often costly and intended for large-scale applications. Attempting to use the same solution for a small household hydroponic operation may not provide the same results.

The ratio of nutrients may not be equally distributed throughout the solution. Your plants may end up overfed or underfed.

Preparing organic nutrients involves more work. You need to combine raw materials and pre-digest them before adding the mixture to the water in the hydroponic system.

The plant roots cannot extract nutrients from the raw materials used for an organic nutrient mix. The mixture needs to begin decomposing, which is typically achieved using liquid bio-digesters or worms.

Using organic food made from raw materials also increases the risk of excess bacterial activity and algae growth.

How to Deal with Algae Growth in Organic Hydroponics

Raw organic materials are more likely to promote algae growth, requiring you to keep up with the maintenance of your hydroponic system. Keep an eye on all areas of the hydroponic farm to monitor algae growth.

If you notice green growth around the tubes or net pots, choose a suitable time to remove the growth. Use an old toothbrush, a Q-tip, or a paper towel to wipe surfaces clean.

Some components, such as tubes and pipes, may need to be removed for a thorough cleaning. If you need to remove components, shut off your pump.

Water tanks should always be covered with dark material. Exposure to light increases the growth of algae and bacteria.

You should also thoroughly clean all the components between crops.

Some hydroponics methods are also more susceptible to algae growth. Passive hydroponics, which relies on stagnating water, is more likely to promote algae growth and bacteria.

The NFT systems and deep-water culture (DWC) systems use a continuous flow of water, which reduces the risk of algae.

Recipe for Homemade Organic Hydroponic Fertilizer

Homemade fertilizer is typically made with compost or worm castings. Both options contain the nutrients needed to feed your plants. However, you cannot just throw compost or worm castings into the water reservoir.

The compost or worm castings are added to a water solution and allowed to sit. The raw materials break down in the water, creating a nutrient-rich solution that can be added to your hydroponic garden.

Compost is not ideal, as you never know the nutrient ratio. It’s made from broken-down organic material, such as leaves and vegetable scraps.

Worm castings are more likely to contain the nutrients that your plants need, as worms obtain nutrients from healthy soil.

Quick Pro Tip: Setting up a worm farm offers a convenient, fun way to pre-digest nutrients for your hydroponics system.

Whether you use compost or worm castings, place the material in a mesh bag. Place the mesh bag in a large bucket of water, such as a 3-gallon to 5-gallon bucket.

If you have hard water, add a few drops of lemon juice before adding the mesh bag. Squeeze the mesh bag and allow it to sit overnight.

After you remove the bag, you have a bucket of nutrient-rich water.

Some hydroponic gardeners add kelp to the recipe. Kelp contains a wide range of vitamins and minerals that can promote healthier plant growth.

Place a few handfuls of kelp in a 20-ounce water bottle filled with water. Allow the kelp water to sit for several days until it turns light green.

Pour the kelp water into the nutrient-rich water and mix thoroughly. You now have an organic nutrient solution.


So, can hydroponics be organic? The typical hydroponic setup is not organic, as most people use liquid plant food that contains synthetic ingredients. If you want to grow organic hydroponic plants, you need an organic solution instead of a synthetic fertilizer.

Creating a homemade organic fertilizer with compost or worm castings offers a natural way to supply your plants with nutrients.

If creating a homemade fertilizer sounds like too much of a hassle, just stick with the synthetic nutrients and rest easy knowing that your plants are still mostly organic.