yeah i think you might be right. come to think of it, i have never really checked the temperature during the night (dark cycle) but during the day it stabilizes at about 22°C (approx 71°F) so it should not be dropping down that much (55°F seems a bit excessive) at night.

i should have turned on the heater though! ah well, next time =p

anyhow, thanks for your input =)