KNO3, K2SO4, KH2PO4 can all be purchased from
www.litemanu.com. They also sell the chelated iron. Plantex CSM is available from
www.jrjohnson.com. The joke is that Plantex only comes in 5 lb tubs which is a lifetime supply and more for most anyone.
But the real thing here is if you don't know what these items are then you should not be attempting to dose with them. I still use Flourish and I don't see how one can figure it's expensive.