Size of sponge filter?

[markwill]

I have decided to add a sponge filter to my show tank specifically for the purpose of being able to quickly move to a hospital/quarantine tank. For now, my hospital tank will be a 29 gallon tank but I may get a larger tank (55 or so) later.

I don't want a huge monstrosity in my show tank but do need to be able to move to the hospital/quarantine tank quickly with sufficient bacteria. Just because others have used them successfully, I am going with Hydro sponges. What size filters should I get?

Thanks.

Mark

[Carol_Roberts]

IV or 4

[Cosmo]

The nice thing about the hydros is you can put a small airstone in them, so you get smaller bubbles, and quite a bit less noise ...