I have a 100 g custom viv...poorly made I must add. It has thin glass. Thinner than a aquarium glass would be. Anyways I am battling temps. My basking bulb from zoo med blew. So I scoured this sight and tried incadescent and halogen. I had a 60 w halogen... No dice. Temps too cool on basking. 100 w incadescent doesn't seem to be doing the trick either. He has never basked on a basking spot for long. He is either on a limb or on a rock that is attached to the wall, I moved the limb to under the light so he could get up closer but of course off he goes to the rock or hammock. The temps in either area are 70- 85 the temp on the limb close to the light I have at 90 it is 10in from the light and I can't get it closer and I doubt he will stay on it if I did.... I think it is the viv. The glass does not allow for any form of insulation. I love it because its 5 ft long. He has lots of room. But I'm sure if I tried to mount the light inside to get it closer to him a clamp would probably smash the glass. Ugh. Any ideas? We will build a new viv...but right now it is not possible. Where I am temps outside are fluctuating as well as fall is here and winter around the corner.