Tom said:Leopards and sulcatas are not prone to shell rot. It is very uncommon and would only come from long term horrid conditions or a shell injury.
Yes your heat lamp does dry out their shells. That is why we soak them daily, spray their shells, and maintain high humidity and humid hide boxes.
Tom said:If the whole enclosure is warm, I don't think it matters which side which is on. My inclination is to have the humid hide they sleep in stay warm, so I'd put that under the CHE since its on at night too.
It kind of all depends on the temps and conditions in your enclosure.