I just purchased a used ars 7030. I have a some questions with it. 1...Rust. It has some rust on the underside were the tub slides into. Can anything be done with it or will it be ok for the snakes. 2....humidity. It doesn't have removable tops to change, and it has the built in cup holders for water. My room has a heater and I keep it about 79-81. My previous racks I used news paper and large water bowls. What substrate are you using and how do you keep the humidity up? Should I switch to Reptichip and mist it every couple days? Please Advise....Thanks