Mineral and Nutrient Supplements in Aquaponics Systems.

The question is often asked if there is a need to add mineral and nutrient supplements to Aquaponics systems. The answer is both yes and no.

In the very beginning, I advocate the use of a seaweed extract such as Seasol or Maxicrop or Kelp and Fish Emulsion as an initial boost for a new system. It gives the new system something to work on and acts as a tonic for the new system aiding in the establishment of the beneficial bacteria..
A new Aquaponics system needs time to develop all the bacteria and microbes that will convert and release the necessary nutrients for good plant growth.

Seaweed Extract

Fish and Kelp Concentrate

Aquaponics systems closely mimic nature in the way they handle and provide nutrients for the plants. Eventually there is a myriad of bacteria and other microbes that do their job, just as they should in a mature Aquaponics system.

The job of the two main beneficial bacteria in converting the ammonia produced by the fish to nitrates is very obvious. They are established in a new Aquaponics system usually within a few weeks. It takes time for all the other natural processes to develop and establish.

This is the amazing thing about Aquaponics . The way it becomes so balanced and complete.  Aquaponics is an ECO system.

I also advocate the use of “worm extract” or “worm juice” as it is sometimes known. This is done to help “kick start’ the mineral and trace element build up in your new system. Worm juice is not always available to you so the Kelp and Fish Emulsion is a good standby to get your new system up and running.
It should be applied at the rate of a CAP full a day.  This can be continued right up to and past when you add the new fish to your Aquaponics system.  Our Fish and Kelp Concentrate will not harm the fish.  Natural organic mineral supplements work slowly and are not like chemically derived fertilisers.

Fish and Kelp Concentrate, or Seasol or Maxicrop can be applied once every three or four months to assist in a balanced mineral load in the system, and as a tonic for the Aquaponics system.

It is a good idea to add it at the grow bed water entry point and allow it to peculate down through the grow media and make it’s way around the system carried by the water.

You may find it a good idea to add a half a teaspoon of Chelated Iron to one of the grow beds once a month. Iron deficiency is often encountered in new systems. This is most often a symptom of “Nutrient Lock Out” caused by pH above 7. As pH stays above 7 nutrients are locked up and are not available to the plants even though they may actually be in the system.

Aquaponics systems run best at pH 6.2 to 7.0.

If adding Iron, just use a little water to wash the Iron down in amongst the grow bed media. The Chelated iron can also be added straight down into the water beside the auto siphon device.
This way the iron will be dispersed more slowly around the bed/s. Even though it is added to just one bed, it will find its way around through the entire system.

Potassium and Calcium are also needed in Aquaponics systems. If feeding your fish on commercially available pellets these two elements are often in short supply in your aquaponics system.

These two elements are easily supplied as part of pH control / adjustment.

Practical Aquaponics.

8 Responses to Mineral and Nutrient Supplements in Aquaponics Systems.

  1. Jimmy Bell says:

    I would like to know what type and were should I get the following items from this page.
    Cheated iron
    Potassium
    Calcium

    • Murray says:

      Hi Jimmy,
      Chelated iron is available from most garden shops. It is most often in powder form.
      Potassium is most easily found in the form potassium bicarbonate. This can be purchased most easily from “brew” shops. It can also be obtained in some garden shops and is sold as an organic foliar spray to assist in the control of mildew on plants.
      Calcium is obtainable at builders hardware stores as “Builders Lime” or “Hydrated Lime” This is used to adjust pH when necessary and happily adds calcium to the system in the process.

  2. Jimmy Bell says:

    Thanks Murray

    I appreciate your time. I feel like my system may need something because although my plants are growing they don’t look as vibrant as yours do. One thing you mentioned in that page was that the plants could all of a sudden the could stop getting nutrients from the fish. I feel that has happened to me a few weeks back. When it did the amonia spiked and I was out of town and all my fish died. So I cleaned up the mess and started over. I want to try and prevent that this time. I’m hoping to maybe meet you in Orlando at the 4day school one year but not this one. Anyhow Thanks

  3. Stefano Zamprogno says:

    what about ATAMI Alga-C ?
    Is it a seaweed like your Seasol ?
    Hope it is not harmful for fish.
    Thanks!

  4. Gena says:

    Hello, we have a floating raft system over a 300 gal. tank with talapia fish. Our strawberry plants are showing what I think is calcium deficiency , browning around the edges of old and new growth. Our pH is running a little high 7.2-7.5. Any info would be greatly appreciated. Thank you, Gena

    • Murray says:

      Hi Gena,
      Calcium is easily added by using hydrated lime, this will however push your pH up. pH can be lowered by using hydrochloric acid. It is cheap to buy, use sparingly, wear gloves and eye protection. Us a cap full, wait a couple of hours, re test the pH and see how it went. Repaat as necessary.

  5. Steve says:

    My plant steams are turning purple. I believe magnesium deficiency. Will garden lime cure or what is a good cure for aquaponics system that wont hurt the fish

    • Murray says:

      Hi Steve,
      Most of those micro nutrient problems can be fixed by the application of seaweed extract. Choose a good brand such as Seasol in Australia and Maxicrop in the USA.

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