I'm not sure if it's powdery mildew, I sprayed it right off with a spray bottle. Which if the stuff is powdery, would make sense if it just vanished lol. But it doesn't seem likely that it is powdery mildew, considering the environment my plants are in 79-80 degrees with a humidity of 35% today cause it was freaking hot, and couldn't bring myself to turn the a/c on. I recently had a magnesium deficiency in this, and another plant. Solved it with correcting the PH in those containers, and for the quick fix I put 2 tablespoons of epsom salt in 1 gallon of water. I'm thinking the white mineral could just be salt build up from me misting the plant with water that has epsom salt in it? Would powdery mildew simply spray away if found? Lots of questions here, no pictures cause as I said the shit just sprayed away.