yep. will not take that long either. there are a few products to treat it like green cure, serenade and mildew cure. those are what we sell. start over if you can afford to. if not pay $200 and get a sulfer burner and sulfer pastiles, burn when the lights go off twice a week and you will not see...
it's powdery mildew. it's a fungus that gets in your plant like herpes, you can treat it but it will be there in the blood. get a sulfer burner and get new genetics after you harvest. clean your entire room from top to bottom with peroxide water. start over. sorry for your luck. i work at a grow...