what i have now is 2 UTHs each hooked up to a thermostat to make a heat gradient mines 82-92 atm and it keeps ambient at like 81 ish and i have a glass also.. dont use a light unless you want to mist every 2 hourssooo time consuming lol..
and btw its easier to keep substrate temps good with repticarpet.. not as much insulation for the heat to travel through
and by the time you have washed it like twice its payed for itself compared to natural substrates
edit: this is were i learned http://ball-pythons.net/forums/showt...ass-tank-setup at the bottom it shows were to put your probe