Is Organic Hydroponics Always Better?

By Frank Rauscher
Published: December 1, 2016 | Last updated: April 27, 2021 12:17:54
Key Takeaways

Is organic the only wise choice left out there? Let's start by deciding what it means to be truly organic in the first place, and then apply the concept of organics to a hydroponics system.

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There is a lot of buzz and interest in organics. What is organic? What isn’t organic? Are Hydroponic systems organic? Opinions on this seem to cover the entire spectrum. But what is real and what is marketing?


A hydroponic system can be organically operated. Take a hydroponics system or an aquaponics system for example. There is no more need to use synthetic fertilizers or pesticides in a hydroponic system than there would be in a conventional garden grow.

Actually, due to the fact that many hydroponic systems are indoors or at least within a greenhouse, the reduction to exposure to large populations of insects can help to operate a hydroponic system with minimal use of any chemical pesticide.


To really get to the root of this issue, however, we need to begin with some definition clarification. The term organic seems to have an extremely wide variation of definitions and, therefore, differing opinions on the matter.

Organic Terminology

An organic compound is simply one that is carbon based, but there is no official scientific definition of an organic compound. This is why there is a need to use caution when hearing the claim that something is organic. Broadly defined, the dictionary entry for organic is any of the following:

  1. Of, relating to, or derived from living organisms: organic matter
  2. Of, relating to, or affecting a bodily organ: an organic disease
  3. Of, marked by, or involving the use of fertilizers or pesticides that are strictly of animal or vegetable origin: organic vegetables; an organic farm
  4. Raised or conducted without the use of drugs, hormones, or synthetic chemicals: organic chicken; organic cattle farmingo
  5. Serving organic food: an organic restaurant
  6. Simple, healthful, and close to nature: an organic lifestyle

In regards to most of the questions I am asked about organics, the above definitions 3 and 4 are what most folks are interested in learning about and what, for the purpose of this discussion will comprise the current, popular definition of organic.


Organic growing will not use pesticides and fertilizers that may have risky synthetic chemicals in them. What seems certain is that consumers and growers alike want as natural and as safe a growing process as possible with maximum productivity and taste. A clearer understanding of pesticides and fertilizers could help us achieve this.

Organic Pesticide Options for Hydroponics

Pesticides that are derived from animals or plants, and not combined with other synthetic chemicals, are considered organic. Synthetic is a key term in this aspect of the discussion. For example, a pyrethrin is an active component of a chrysanthemum flower and is available without the substantial process that might render it synthetic. Pyrethrins on their own are not really effective in killing many insects but do a good job of stunning them and making them vulnerable to being killed by other toxins.


A pyrethroid is an organic compound because its molecules contain carbon. These compounds are not extracted from the chrysanthemum but created through chemistry. They are synthesized. They do, however, have very similar characteristics to pyrethrins in both efficacy in controlling insects and safety towards mammals. They are actually a significant improvement over the naturally extracted pyrethrins.

Permethrins (second generation pyrethriods) use a common chemical piperonyl butoxide (an organic compound) added to do the job of actually killing the insect. Remember that just because it is an organic compound doesn’t mean it isn’t synthetic. This one does, however, have a low oral and dermal toxicity to mammals while being quite toxic to insects. It sounds desirable, but as it is combined with a synthetic it is grouped outside the current popular definition of organic.

I present this very complex and potentially confusing information in order to get everyone thinking outside the regular box known as organic, and to help give some good balance to an understanding of just what products you may want to use in your garden. Manufacturers can use the claim of organic simply because the molecules contain carbon. What is vital to look for is that the products are groundwater safe and safe for mammals.

On one side of safety considerations would be synthetic systemic pesticides that pervade the plant tissues and are subsequently available for consumption if the plant is eaten. It is clear we want to avoid these.

There are pure, popular organic pesticides that are safe for mammals, but perhaps not effective if used improperly or used to control a pest they are not effective at controlling. Then, on the other side, there are some long used and safe compounds we can trust to stop severe infestations. Having a better understanding of all these should give the grower maximum success.

Keep in mind there are pests out there other than insects. If not beneficial, bacteria and fungi are also pests. So, pesticides are not just for killing or controlling insects, but are used to stop or minimize disease.

Some bacteria can be very dangerous to a hydroponic system. Once pythium gets started in the fluid media it can cause the entire crop to fail and create toxic by-products. In any type of system, the prevention or control of pathogenic pests is vital to not only the garden’s yield, but to the edible safety of the crop.

Is it a good practice to simply discard all pesticides that might be classified as non-organic and put other risk factors at a higher level? Carefully evaluate just what is synthetic, what the risks are and what the trade-offs are for plant health and food safety. Always favor the organic option first, but keep other options on the table if needed.

Consider many of the food toxicity incidents in the past few years, and just how many were from organic farms. As our current industry standards call for strict avoidance of synthetic fertilizers and pesticides, this often makes the task of maintaining plant health and food safety difficult.

I believe we need a new way to grade how our food source is grown—one that takes the level of risk in all areas into consideration and gives some sort of simple color code chart for the consumer to view and use to help them make better choices.

Fertilizers for Organic Hydroponics

Many fertilizers that fit under the popular definition of organic are primarily derived from some type of animal waste so there needs to be great care that micro-organisms are properly controlled in order to prevent pathogens like E. coli.

Also keep in mind there is a strict requirement to use only organic pest controls to do this. Many companies are indeed capable of doing this, but it is no easy task. Look at the trade-offs before deciding.

Plants require adequate amounts of the three macronutrients: nitrogen (N), phosphorous (P) and potassium (K), but also require micronutrients such as iron, zinc, manganese and copper, etc. How are these plants being fed to assure that these essential heavy metals are available in trace amounts to provide plant health?

No matter if a plant is grown in garden soil, or in a controlled hydroponic environment, these nutrients can become too scarce and the plant can subsequently suffer from this. A practical method for avoiding this is to add a safe micronutrient supplement to your organic nutrient.

Though these nutrients can come from natural sources, I have not found a balanced combination of all (or even most) of the needed micronutrients in an organic fertilizer. Good soil will likely contain adequate amounts of these nutrients but will eventually become depleted.

It doesn’t do much good to avoid the use of a safe synthetic and at the same time subject your plants to nutrient deficiency. A balanced practical approach to nutrient selection can go a long way towards optimal yield, plant health and the ultimate value of the food produced.

Don't Forget about Naturally Present Organic Toxins

Toxins are in our food even if we never apply a synthetic substance. Cyanides are organically created toxins or poisons, but just because these are organic certainly doesn’t mean we want to expose ourselves to dangerous amounts of them. For example, apples contain cyanides, but in low quantities they are not harmful.

You can’t achieve the goal desired by dealing with this in the extreme. There is the type of common sense we all need to use when we consider what we are willing to allow in our food source, and what we add as supplements to our garden.

There are trade-offs, of course. To use a small amount of a low-risk chemical (whether synthetic or naturally organic) in order to, for example, reduce the likelihood of botulism, would seem quite practical.

Some of these chemicals can cause many maladies when used in high enough concentrations and used over a considerable period of time. Salt is a chemical that we feel pretty safe with, (yes, salt is a chemical) but just consider people with hypertension and we see even here that we need to be careful.

Then on the otherhand consider that C. botulinum thrives in moist foods that are low in salt (less than 10%). It is therefore a good preservative to use if you are not pre-disposed to high blood pressure or a number of other issues.


Going organic is great, and making your hydroponic system as organic and safe as possible is the way to go. Just because it is hydroponic doesn’t mean it’s synthetic, or that it needs to be. And, just because a product is claimed as organic doesn’t mean it is necessarily safe or effective.

A balanced approach will give you the very best options for safety, yield and taste. Don’t automatically exclude something because it is classified as a synthetic compound. Look into it, do some research and then make your choice.


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Written by Frank Rauscher | Writer, Owner of Garden Galaxy

Profile Picture of Frank Rauscher
During his many years of service in horticulture, product development and sales, Frank has performed innumerable visits to landscapes to facilitate a correction for struggling plants or assist with new design. He also writes for Southwest Trees and Turf and The Green Pages, is the owner of Garden Galaxy and manages several websites. He has four children and eight grandchildren.

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