Leopard gecko... no, I don't beleive so. Like oceansh said, Leos love desert settings. It would be too moist. Mostly people just put a moist hide and that is it. They need dry setting too.
I think that fits a type of newt or salamander (I really dont have no experience, so correct me if I am wrong)... most definetely FBT though.
I think you should try to research on some pet amphibians that can swim, climb, and love moisture.
Overall, I love the tank. I wish I was that talented, and it is your first time!!
