im looking into a fluval canister filter for my 30 gallon tank i have one of their internal filters and it works ok but im looking at the big canisters does n e one have experience with them and no if they are good i do have a turtle in this tank so there is alot of junk along the bottom and such if n e one has n e experience with a good filter for that or if they know if the fluval filters are good n e help would be appreciated