Beth,
I assume you are talking about bearded dragons? If so, do a Google search on them. Lots of info out there.
One of the sites I found talked about using natural substrate. When we set up our ball python tank, sites we found also talked about using natural stuff for substrate, so that's what we used. However, it was VERY hard to keep clean and we switched over to using towels cut, with edges sewn so they would fray during washing, to the size of the tank bottom. When we had the snake at the vet, he told us using towels was a good way to go. Once it gets soiled, just replace it with a clean one. We've got four such towels and swap them easily whenever we need to.
Sounds like you have the same kind of enclosure as we do with the sliding doors. Bottom has wire mesh in the glass. Top is strong wire mesh. Good luck with your beardie
