Leaves hooking

Anybody know what causes this, only 1 plant has done it so far. Ph is good, 10-15-10, 300w cfl, plenty of pot room.

and what is your good pH?

and what medium, nutes what ec is it on the new growth at the top of the plant ect more info the better also a pic would be good as there area few things that can cause this

Sounds like overwatering buzz.

View attachment 2012-12-03 05.11.24.jpg
Not sure why first pic didn't load. Ph color chart says its about 6.7ish, old fan leaf, soil and verm mix.

those color ph drops dont work well and are off often. Get a PH pen on ebay for 30 bucks and get the cleaning solution, storage solution and 7.01 balance. Keep it 6.2-6.5 ph including nuts. Hard to tell with this little info.