Krisisanswered grow question 8 months ago I don’t have an actual answer for you, I just came to tell you that my permanent marker had this same thing happen. The half light and half dark thing changed to red on the light side. I think that happened at about week 5 flower. The leaves are still there. Still split red and green lol if it caused any problems? I have no idea. I freaked out about it back then but alls good. Only thing I could guess at was I had overfed nitrogen .. got a magnesium deficiency and it didn’t get enough micros at that time. I continued on dropping the grow part. Like zero and giving bloom and a cal mag with micros that claims to have no nitrogen