can someone please help me find the right filter for m map turttle? right now he's in a 20long(i know too small but it's small and will upgrade it when it gets bigger) so need one that will work with that and maybe move along to a bigger tank when need be. but it doesn't have too. a few i've been looking at are zoo med reptiles 501 and for odd reason Tetra ReptoFilter. please let me know what will be the best filter to get.. can't spend alot of money on it right now or i would just get a canister