What causes leaves to brown and curl? I am growing a Girl scout cookie from Nirvana Seeds and a Gold Leaf from ILGM, photoperiods in coco coir, with organic dry amendments. I am also using RO water which I supplement with cal mag once a week, and also feed molasses once a week as well. But during flower phase, the leaves turn brown and wilt. I am using a SPIDER FARMER SF-4000 LED Grow Light in a 4X4 grow tent. I am wondering what am I doing wrong? Please if anyone knows I would really appreciate the guidance.