Question on Dosing Potassium
Got my stuff from Greg Watson and read Rex Grigg's web page. My question is, Chuck Gadd's calculator gives me the K from KNO3 and the K from K2SO4, so I can figure out how much K2SO4 to dose. He omits the K in KH2PO4, but I'm assuming he knows what he's doing, but I'm curious as to why we can ignore the K in KH2PO4? Is it because that K is not usable?