I meant to ask after your earlier post, greendoctor, if you were using greenhouse grade potassium nitrate. Appears that you are if you making your own mixes and spraying.
Is it difficult to get in Hawaii? I use prilled potassium nitrate and it is terribly hard to get. Spotty. Available some years, other years not at any price. Used to be one could understand the big price swings that came with peace or lack of peace I the Middle East. Now that Homeland Security is involved, shipping interstate has become slow, onerous, and expensive. Most places want nothing to do with it. I found a couple pallets last summer and have been using it sparingly. I have also had to put up with a lot of BD and inconvenience. Where I normally would not accept product that is rock hard, I have found myself breaking up bags of potassium nitrate with a sledgehammer and my 'blew tool', one 50# lump per bag, in a sturdy wheelbarrow, screening it into 5 gal pails, then adding to my tractor mounted spreader. I tried adding a clump bar to the spreader but quickly saw that it was going to tear up my spreader before those rocks would be broken up.