Hi PharmaCan, in my Cervante's book it says to avoid powdery mildew you have to keep it well ventilated, well lit, and keep a low level of humidity. That's what I did with my two and they got it and died anyway. I even Serenaded (and not with my awful voice!) them once a week, but they were too sick. I'm sure you know all of that anyway and have all of those scenerios covered. I thought the way to keep it away was to sulphur bomb, but you already do that. Sorry I am not much help, I would love to see if someone knows the answer. Take care PhamaCan and Happy New Year! :stoned: