What is iron chelate?
This is a form of iron that is bound to another chemical that makes it available to plants over a wide pH range. The most common one in Hydroponic nutrient formulas is known as “EDTA,” which produces a form of soluble iron that is very resistant to oxidation by peroxide or ozone treatments. This form of iron is also very resistant to forming insoluble precipitates, over a wide pH range. In soil, humic acids perform a similar function. Other elements may be chelated also.