Calcium? Phosphorous? Iron?

I had a lot of questions going in to this phase of research about how to supply the needed nutrients to the system without having to buy chemical substances. I haven’t found a lot of resources online or otherwise about this. Max Meyers had quite a few ideas…
Snails, crustaceans, prawn shells can be dried and fed to fish to increase calcium, or ground into a fine powder and added directly to the system. Shells can be added to the filter to allow calcium to leach into the system as needed. Chicken manure as well as other bird droppings can be added directly or composted and added to supply potassium and phosphorous. Iron can be supplemented by creating comfrey tea. Allowing the leaves to soak in water for a week, strain/drain and then add the water to the system. As well as seaweed, dehydrate the plant matter and then crush and soak in water for a week, then straining the solids from liquid and adding the water directly to the culture water. Other dynamic accumulators can be used, the same plants that leave nutrient residues in the soil for other plants to consume can be used in aquaponics as an additive. Blood can also be used to add iron to a system. Rusty nails do not produce the right kind of iron and should be avoided.

5 thoughts on “Calcium? Phosphorous? Iron?

    • If you add crushed shells the water will leach the calcium out as needed as the PH shifts. Are you worried about clogging pipes or building up in the water?

  1. At the meetup for the Clovis Aquaponics System, someone mentioned that the plants looked like they were Potassium (K) deficient. This made a lot of sense to me as the food I add does not have a lot of K in it. After consulting with John Young (J&J Aquafarms) I determined to try Greensand. (Glauconite, a marine deposit composed primarily of iron-potassium silicate.) It is an all natural source of iron and potassium and contains over 30 trace minerals.

    It is not toxic to the fish and will self regulate the K and Fe levels in the system. I am also going to add some oyster shells to add Calcium to the system.

  2. Great info in the nutrients!
    Any updates by now (it’s been a while since you originally posted)?
    What exactly you are doing for nutrients in the System? What did work and what not? How about dosing (thinking of larger systems too)?

    Thank you for your work.