I have my ball pythons heat lamp hooked to a timer so its on for about 13 hours a day. He also has a UTH that is on all the time. Is it ok that his light goes off at night and the ambient temp goes down, or should i be leaving it on all the time and getting a dark night light. during the day with the heat lamp the coldest part of the tank stays about about 80 and during the night the coldest part stays at about 75.