You probably got a bacterial infection and over fed. Are the fungus gnats wreaking havok? Get some Atak,water with and spray with transport and I bet they snap out of it. May take a week or two but you will see improvements fastHappy 420 everyone.. I think I got the virus.. purple stressed stems stunted plants mosaic viruse pattern half yellow and hooked leaves spots on leaves resemble cal mad def, , Got a GG4 a year ago and all yields dropped 50 % Now BB of 20 years AK of 10 years now Infected they all have to go. Not going to put up with this . here is a link with what my leaves look like.