Good for my PET RAT? or not?

Well, if you get a daily newspaper you could shred that and use it, but you would need to clean the cage often (especially since it's an aquarium) probably 2-3 times a week. Cloth or fleece can work but needs to be changed out every other day, also some rats will rip it up an use it in their beds. Carpet does not work because it absorbs urine and can't be washed. By shelves do you mean shelf cages? If yes than I have read they do very well, and apparently don't chew through the wood. But you must put lino or fleece or towels or something on the wood.