the problem is he only has 3 legs, and sometimes he is a bit clusmy! So i do not want to make the cage higher, i want to make it longer. I've been using the pvc tube for over a year on his cages now, and i've had no problem. He doesnt even notice it. Plus he cannot chew the plastic because its hard as a rock and its inside the tube. A contractor set it up so the outide part thats inside is metal. Hard to explain but is safe. Im constantly checking it to make sure (im a freak about his safety). The plexiglass is very small in comparasin to the entire cage which is huge! Im removing one small panel, not the entire side of the cage. I keep my apartment at a constant 60-65ish degree and the plexiglass will not be near any sunlight or heat source so I cannot see how it will raise the temperature inside the cage considering the entire rest of the big cage will be out in the open. Plus the plexiglass will be on the bottom half which is very close to the floor (its on wheels) and its colder towards the floor than it is higher anyways. I'm also thinking about asking my friend who is making this to drill some extra holes in the plexiglass to ensure more air flow.