i have a perpetual grow going and i keep getting powdery mildew... ever since i had a white widow plant flower and it seemed to spread to everything which was a few months ago... i have sprayed everything with the "green cure" during veg and all the flowering plants a few times. the temps are around 75-80F and according to my thermometer the humidity stays between 30 and 40% the ventilation of exchanging fresh air is up to par as far as i know, same as it has been in my recent grows w/o pm.. no matter what i do it keeps coming back. i didnt have much air moving everything around in the tent(just a large fan blowing heat off of the light, so i threw an oscillating fan in there to blow air around the lower parts of the plants. will this help? i do not like spraying them with chemicals during flowering because it fries the pistils, makes it look like trash, and leaves a residue. i have 6 plants mid flower but the one i noticed it on today is 5 weeks in, on a 7 week strain. do i have any options besides a sulfer burner? should i foliar spray with high ph water ~8.0 and use a dehumidifier to finish it out?