in my 10 gal molly tank i currently have one of those filters thats a plastic box with sponge things inside. not real sophisticated, but it was good starter. now i want something a little more powerful and that will actually filter better. any suggestions? don't want anything too big or expensive (thinking the $20 or less range). need something that will still create a current (the fish like to play), isn't going to be super noisy (boyfriend has already banned fish tanks from the bedroom), and won't take up much room in the tank (currently located in a corner of the tank). thanks!!!!