Using two UTH's would cover basically the whole tank and cause your BP to unsuccessfully thermoregulate. Tanks are a pain to keep temps and humidity up. Go to your local wal-mart or lowes and buy an appropriately sized rubbermaid container. They are cheap and are great for enclosures. MUCH better than tanks. Then if you have the UTH on a dimmer you can set it under 1/3 to 1/2 of his tub. Then adjust it until you have the right temperature and then move him in. He'll have a much better chance of being healthy in the tub, and you wont have to worry about the temps in the glass tank.