That might sound dumb but most of the places that sell everything else do not sell just K in a dry form. Am I missing something? I have a gallon bag of muraite of potash,but I have no idea how much of that to use so I would like to buy what I need.
I'm not sure if you CAN get raw potassium as it's a metal and if you could it'd probably be from a lab supply store or something of that nature. You could probably get away with using K2SO4 which according to GLA is 44.9% potassium.