The ambient temp of the room your herps are in usually has a good deal to do with the temps inside their enclosures. No matter how warm you put the heating pads if the air circulating around and through the enclosure is still going to try to level itself out with the air in the room. I know i had a heck of a time when i first got a bp keeping the temps up in the room. It was Feb, and the apt i was in didnt have any heat ( long story ). I had to get a space heater and place the heater and the tank in the closet just to keep the temps up so the little guy would be ok. At the time i was using two heating pads and a 150watt CHE to try to keep the temps up and it was not working. I know that may be an extreme example, but something to think about. I try to keep the temps in my herp room now at a constant 75-77 degrees, at the lowest end of the cool side temps. That way i really dont have to use but one heating pad on low.