Yeah Roast if the curling is due to to hot or dry then you would be right mate, humidity is only 15-30%, I have 2 towels in there hanging up which dry out twice a day. I water the towels in the morning and before I go to bed, dry each time. The humidity must get sucked straight out as it evapourated off the towels. The temps get to 37 (100) max temp with a min of 20 (55) daily, can't help it with this HPS light in there. I suck air from my sub floor which is always cold... fucks me what to do