The origin of hash plants

Day 70. The Afghani is doing mostly fine, I just see the problems on the leaves again. At first sight it looks like some deficiency, but since mostly the upper leaves are affected, I'm beginning to suspect it might be too much light. I'm using more light than recommended by the manufacturer anyway and I'm keeping the lights very close, maybe too close. So in my next grow I will follow the recommendations and see if this makes a difference. Apart from that, very nice grow. Looking forward to the end result. Probably two more weeks to go.