I use a 5 quart rubbermaid with a lid (with hole cut in lid) and about 2 inches of water in it. If the lid is kept off, he only cruises through it and to get a drink now and then, but if the lid is on, my BP likes to get in it and use it as a hide. I usually only put the lid on it when he is in shed mode because if the lid is on, the humidity drops about 10 percent. Just have to mist occasionaly due to the lid being on.