So I got my wife one of those "beginner" turtle tank setups they sell at Petco for Christmas. We had to get a smaller than legal baby red eared slider (he, or she, was only about 2" long when we got him) from a local pet store as the Petco had sold out of them. We've had him in the 20 gallon tank now for the last 8 months and he seems to be doing very well. He's grown to almost 5 inches long. We clean out the tank about once every 2 weeks and change the filter inserts. About once a week I change out about 20% - 30% of the water and I treat the new water before it goes in. We have a heater which keeps the water at about 78 degrees. We initially had gravel in the bottom of the tank, but took that out as it was a pain to keep clean and he seemed to want to eat the smaller gravel. So now it's just the filter unit (which is the one that looks like a decorative rock), his turtle dock and the heater.
It looks as though we will have to get him a larger sized tank, as he has pretty much outgrown the 20 gallon tank. I'm thinking of going with a 40 gallon tank and an external canister filter. I would like to get him a 55 gallon tank, which I know one day he will need, but space considerations at this time dictate a 40 gallon tank. I've done some research on canister filters. At first I was looking at the ZooMed 511 filter, since that is the one that is included with another one of those turtle tank kits they sell. But after reading quite a few reviews, I think I have settled on the Fluval 406 canister filter. When we are able to upgrade to a 55 gallon tank, we should be able to continue to use the Fluval. I also looked at the Rena XP3 filter, but saw some reviews which said that filter is prone to leaking, which we can't have. Any recommendations on possibly a different filter, or any help in setting up the larger tank?
I'm sure there are things we are doing wrong taking care of the little guy, so I'm glad that we found this forum to hep out with any questions we have.
Thanks!

