So I went to the local store and they put together a kit that included a heat pad and they told me to put it on the underside of the tank on one side. I have done this and I have noticed that the substrate dries out quickly on that side. We keep a spray bottle near and wet the tank and substrate often. what I have noticed however is that "Pac Turtle Tortoise" (name of baby pacman Frog) only hangs out and burrows on the side without the heat. Additionally he isn't eating much and or moves around much (or we don't notice if he moves around at night.). I live in San Diego so the temp in the house doesn't get too low 68 is the lowest it's been in a while. My sons room is a darker room in the house and I am wondering if we should open the curtains each morning to let in light. Let me know something I have seen some people day the heat pad is not the way to go and that the frogs should have a normal sun to night time condition.