OK, I admitt I'm another who never listened in chemistry. I cannot get a hold of any Potassium Sulphate as directed in the PMDD menu. What I do have is sulphate of Potash (Potassium Oxide K2O) Is this OK to use, safe etc. I'm a little paranoid about adding these chemicals to the water. As for the trace element mix, I've sourced one from 'Chempak', anybody tried it?