My BP is about 20" long. But I thought since they get like 3-4' I'd get a big tank (40 gal. long). Now since I've been comming to this site I've heard of people usuing 20Ls.. Is that really big enough? I have my Leopard Gecko in a 20L and he loves to run, climb and explore. So I was thinking of cleaning both and putting my BP in the 20L and my Leo in the 40L. Any opinions would be appreciated.