Iron Chelate (FeEDDHA) - 1kg

Plants show iron deficiency by growing yellow leaves with green veins. Iron has a number of important functions in the overall metabolism of the plant and is essential for the synthesis of chlorophyll. The most cost effective method of supplementing iron is with EDDHA Iron Chelate which is a food grade nutrient available online or in store. Use 10g per 1000L to raise iron chelate by 0.5ppm, and most systems will require 20 to 40 grams of FeEDDHA chelated iron per month.

This is what I recommend for systems above pH values up to 9.0 (let's hope your pH never gets that high!), and the best all-round form of iron chelate- especially for starting systems. Effective at a broad pH range, FeEDDHA maintains iron solublility in almost all of the water conditions encountered by startup aquaponic systems