Interesting, I thought PMDD covered it all. So I need to hunt down some PO4. Any recommendations in the States?
I ordered this:
PMDD Pre-Mix 1 lb contains 1 part each of Potassium Nitrate, Potassium Sulfate, Magnesium Sulfate, Plantex CSM+B.
Does PO4 = Phosphates? Maybe one that is not...