Icygirl, I worried about melting the plastic, too, that's why I put the red heat bulb on the side of the tub. Here is the link to my setup again:
http://www.ball-pythons.net/forums/s...ad.php?t=59515

He had a CHE lamp to the right of the tub (now a red heat light bulb b/c we stole the CHE for our Rosy Boa). We put holes in the tub there so the heat could get in - the lamp never needs to touch the tub for it to easily get to 90 on his branch near the bulb. The heat pad underneath was for some belly heat and heat to spread out over the floor as well.

Some say to create a heat gradient vertically so that they can move up and down to the spot with the desired temperature. But I prefer giveing them a horizontal temperature gradient like for GTP's - AND creating a vertical one as much as possible, as well.

I'll shoot some detailed pictures of what I mean and post them later.

Good luck!