Since they are baskers, I would recommend the heat coming from above from a ceramic heat emitter, or a regular basking lamp bulb along with your UVB light. You can also get a combo UVB/heat bulb. I have my uro in a forty gallon breeder sized tank and use a 150W flood lamp bulb to get her basking tile between 110-120 degrees F along with a fluorescent UVB bulb with no heat for UVB exposure. I actually turn off all lights and heat at night and give her a nightime drop to room temp (68-70 degrees F) with no ill results, and actually read where it was beneficial and simulated what they are exposed too in the wild. So, if you used a combo UVB/Heat bulb that gave you the basking temps needed, you only need to worry about turning one bulb off at night. I have tried a combo UVB/heat bulb with her cage set up, but even the 150W combo bulb did not get her basking site up high enough. The 150W flood lamp does. Just remember, they need the UVB AND heat during the day.