3 days ago i cut some 1 3/4 styrofoam to fit around the 2 sides and back of my 20 g glass aquarium. i knew that the glass lost heat but i didnt realize how much. before i was ussing a IR lamp on my hot side, along with a 16 watt Desert Heat wave heat pad from Exo Terra and a 8 watt rian forest heat pad for the cool side. by placing the foam around the sides and back of my cage, i now have no need for the IR light and its great. i dont have to worry about adjusting the dimmer on the light. i am using a towel for a substrate which i double up. I also have to cut up smaller pieces of towel to place under my hides so that the temp does rise to much. the thicker the towel between the heat pad and surface equals a lower temp in the hide. for a top i have a wooden top which i cut to fit, and io have 20 holes cut in the cool end. for the hot end i have a screen about 6 " x 6 " which i leave open and everything is running smooth. just thought i would share if someone out there had a simular setup as me.
nate