under filtration in my 29 gallon

[stunt 101]

im looking into getting a second filter for my 29 gallon. right now i have a whisper 30 on it. i have the goldfish in there so the tank is now cloudy green from them. what size filter should i get for them? should i get a bio filter or just a power filter. leave some ideas for me. i want to use the filter i currently have just to get some use out of it so this new filter would serve as a second.
thanx

[daveedka]

Obviously many options to chose from, my personal reccomnedation would be to add an EMP. 280, or an AC 300. The EMP provides slighly better bio filtration, but the AC is more Versatile IMO both are good reasonably priced HOB's. A canister would also work as well as several other types of HOB out there. If you go with any Hob or cannister. Add a sponge to the intake to help keep maintenance and cost down.