I have had this problem for a little over a month now. My fan leaves are killing themselves from the bottom up and it's almost to the top of the plants. I though it was bugs but no, I thought it was nutrients, well maybe... I don't overwater, my nutrients are fed at less than recommended rate, the water pH is 6.5 and the plants are in happy frog soil. Temps are 75 humid 35% under MH 1000. This picture is from a month ago, the plants look devastated now..... This is my fourth post of this problem, if I don't fix it they're dead!