Re: OG Kush needs help!! Please read
I had a similar plant in my first grow (the blueberry, if you want to see it). All leaves were curling back like yours, and they got a dark green color. I think that was nitrogen overdose.They didn't get brown - that must be something else. I flushed her, gave less N from then on and she yielded very nice. The leaves didn't get better but the buds looked fine.