Here's where it gets interesting. I don't know how it could be temp related since I control the environment pretty well. It seems like too much light (they are air cooled) and are 24" above camopy. I've never heard of too much light, though I have 2 1000hps about 3' apart over 4' x 7.5' table --aprox. 70wpsf. I wonder if it is the strain. (CHEESE). When I grew some sensi skunk with it a couple grows ago the skunk did not bleach out. Yes I have CO2 system but not running right now. I was hoping to get this sorted out first. I was thinking the curling edges could be a response to too much light, though it is classic heat symptom. I wonder though as I don't let temps reach over 85 at canopy and sometimes cooler. I hate not knowing the answer, but what can I say--I'm just not talented enough to figure it out.