Dude please take my advice and chuck it! PM (Powerdery mildew) is one the worst infestations any grower can have to deal with and i pray and toke to all growers that have experienced it!!!
Fortunately your not far along with your grow based off the picture. Its a fungus and it floats through the air as tiny tiny little spores and will infect all plants in the same room. Once the plant has it , it PERMANENT! it like a tumor! it attaches to genes! so if you clone that plant! the clone will have powdery milder!
Milk is a great Insta-kill as well as peroxide. a 4 to 1 solution works, but that remedy works well if your late in flower and soon to harvest and cant really chuck a plant that youve been growing for months (unless its out of control).
Another solution (the best solution if you want to kill all in the room) a sulfur burner. A vaporizer that burns sulfur into the air and it settles on the plant. it prevents the growth but does not rid of it! thats the problem IT COMES BACK! if you get a bad infestation my recommendation would chuck all plants and sterilize everything , increase ventilation, adjust atmosphere, and find the Culprit!
I got PM once a long time ago because in my outdoor vegetable garden my snap pease had PM and it must've or i Must've brought it inside!!!!!!!!!!!!
