I am leaning toward over fertilization. I hope you don't have the heater blowing directly on the plants.

Looks to me like too much Nitrogen.
WashougalWonder Reviewed by WashougalWonder on . Im confused by so many different awnsers!! , plz i need to sort this problem out ??? , My leaves are rolling back i am worried they are dieing!!! , they was fine untill i changed the night temp , i put a heater in the room to bring the temp up ,b4 i put the heater on they were a bit droopy , but it has always been doing that when it comes to the end of the light session, but when the light comes back on they perk up , but this time they were just rolling right under , also two days ago i repoted into 14ltr pot from 2ltr pots but all looked well , plz i need expert advice ????? Rating: 5