Thanks for this instructable! Just began collecting everything to start my own farm, but one thing is pretty unclear to me - chelated iron. Could you please write what sort of it do you use?

I found many different brands and forms (fertilizers for different sorts of cultivation, for humans) with different concentrations, addons like nitrogen, and so on. And even more confusing is that most popular medium for Spirulina (Zarrouk’s medium) uses EDTA, but I found out that for different pH you need different sources of iron: for pH lower than 6.0 EDTA is ok, but for pH 6.0–7.0 you need DTPA or HEDTA, and for pH higher than 7.0 you need EDDHA or EDDHMA. That means Fe-EDTA is not a best source of chelated iron and yet they use it. Do not want to experiment at the very beginning...