Hey guys a couple days a go I noticed that my top fan leaves where turning brown and slightly curling up. At first I thought it was heat stress as my plants were almost touching my grow light. I just want to make sure it not some type of Deficiency I though maybe Ca or Mg def. I am also growing autos that have been flowering for almost a month now
Looks like nutrient burn I'm no expert but I've had it before try flushing them that's usually the solution to most problems if that doesn't work maybe your giving them too much nutrients but I won't lie i don't know too much about feed proportions. I would guess that it isn't to do with your light or the highest up leaves would show stress.
I’m actually not use any nutrients since the soil came with nutrients already and since there autos I assumed they would grow faster so I wouldn’t need them and it only appears to be a few fan leaves toward the bottom the leaves look nice and green