Hello Darrin, I believe my Mg and K is low on the total test because the foundational rock is extremely low in those minerals. As for the Phosphorus, here in central Florida we have phosphate mining so the bedrock is high in Phosphorus. This seems to be the case in most central Florida soil tests that I have seen. If it weren’t for this I would think my soil would be naturally low in P as well. With that said the 600ppm of P on my total test is quite low when you compare it to what one would find in a clay soil. I’ll take it though as it’s at least one mineral I haven’t had to add. Oh, P doesn’t leach so it seems even in Sandy soil it can stick around better than Mg and K.