Nutrient Supplementation in Commercial Organic Aquaponics

Posted on Posted in GRG Blog


Part 1What can I use to supplement in commercial organic aquaponics?

Written by: Michael J Brooks, Technical Supervisor – Green River Greenhouse; Peru, Indiana

For AQUAPONICS MAGAZINE’S (“The Scuttlebutt”)


This month’s scuttlebutt attempts to answer a few frequently asked questions by organic aquaponic farmers around the world. This particular column will discuss some of the products – OMRI approved or otherwise – that can be used when supplementing an organic AP system to correct some of the common nutrient deficiencies that are more often a problem. Next month we will cover mineralization strategies; how to get the nutrients into your system, when and how to test for the presence of those nutrients, and the optimal ranges recommended for individual nutrients in an AP operation. As for part-one of this discussion though, we will again, focus on what nutrients are deficient in our system, and what products we should use to correct that deficiency.

There are three nutrients that are generally deficient in an AP system without supplementation. AP systems will not produce the sufficient amounts of iron, calcium, or potassium required by many plants. Farmers must rectify these issues through mineralization in most cases.

Although there are several organic means of achieving the ideal levels of these nutrients organically most are only feasible in smaller systems. When addressing supplementation in a commercial-sized organic operation you must not only find an organic supplement, but also an organic supplement that is available in bulk, and will achieve what it needs to achieve without breaking the bank.

We all know that the most critical element of any aquaponics operation is capital, so we need to consider it always. This not only means obtaining the most product for your money, but also the most effective, and with as little trial and error as possible. I hope this article will eliminate some of those costly lessons for you organic farmers of larger operations.

First for Iron I would highly recommend Lingosulphonate (an affordable product available at ). Lingosulphonate is a concentrate, and should be treated as such. It can be harmful to the skin and eyes. Protective measures should be addressed.

This product will deliver fast results and can be added directly to your system in an amount relative to the size of your operation.

I have experienced much more success with lingosulphonate than the more popular Biomin iron which is a Citric Acid chelate. Citric Acid can destroy bacteria cultures, and cause a loss in capacity to process waste. Biomin also delivers much slower results in my experience.

The best product for the addition of calcium in a commercial organic aquaponics system in my experience would be calcium carbonate.

A lot of the reason for my preference for calcium carbonate versus Biomin calcium has to do with the difference in how they are added to your system. We will cover that in next month’s article.

Unfortunately when it comes to potassium supplementation in a larger organic operation there isn’t much to choose from. The only thing I have found that is allowed in organic farming is potassium sulfate. Although it works well in that it adds potassium to your system, it can create very quick and high spikes in your pH, and just simply cause too much fluctuation in your system.

Many farmers are choosing either not to go organic, or to move away from the certified organic side of things because of the fact that they are forced to use potassium sulfate, and would prefer not too on account of the system changes that it causes.

Most farmers believe the problem lies in the NOP not having set standards for aquaponics. This is unfortunate and we who are a part of the organic aquaponics community should certainly advocate for the NOP’s institution of aquaponics guidelines. Without them it is my belief that at some point it will become the realization that certified organic aquaponics is not achievable.

However, if you are like me you are continuing to chip away at the problems, and do what you can to ensure an organic product to your customer, and part of that process is the organic supplementation of deficient nutrients in your system. I hope these few products will help you achieve that.

Remember to always check with your organic certifying agency before using any product that is not clearly labeled by the Organic Materials Review Institute (OMRI) or otherwise marked as organic by the USDA.

Thank you for reading, that’s this month’s Scuttlebutt! Be sure to check next month for part-two of this article when I discuss the applications of these products.




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