Two thoughts......its occurring in the higher leaves because they are where the plant is sending whatever it is fed. It's not trying to grow fan leaves at this point......it's trying to grew NEW leaves and that new, sensitive growth is what will be affected first; good or bad.

Second thought.....strictly my personal thought/opinion. Thank god your ph IS off....or you'd have burned them to death with overnute already. The ph locking out some of your nutes is most likely what has kept them from frying too much already..

Fix both.....ph AND overnute.

Good luck.

http://boards.cannabis.com/plant-pro...hy-how-do.html