Filter Sizing

[MissT]

I'm in the process of setting up my 20g long tank. I plan on using sponge filters. What size should I get? Should I go for undersized, oversized, or appropriate? Also, how many filters would I need for a 20g long?

 

[michael]

I would oversize. The important thing for sponge filters is biological filtration. Oversize the filter but run it without to much turbulence.

 

[MissT]

Thanks for your reply. Are there any particular brands that are best?

 

[michael]

I get a lot of my sponge filters through Foster and Smith. I like the azoo line. I like sponge filters that stick to the side of the tank or have a small stand. I do not like ones where the sponge sits directly on the bottom of the tank.