Originally Posted by Egrant
So is a sponge filter different from a normal filter, never heard of one? IS it in the tank?
Thanks for all the advice guys!
A sponge is a very basic simple filter, and very effective especially in smaller tanks (up to 55g). It is basically a chunk of sponge material with two tubes (a smaller inside a larger) down the middle; you connect the small tube to an air pump, and the air goes up/down the tubes pulling water in through the sponge. The sponge filters out the particulate matter--just like sponge pads, floss, etc. in other filters--and bacteria colonize the sponge. So a sponge is mechanical and biological filtration all in one. Being small, in a small tank they are perfect. The water current is not great, which is usually preferable for various reasons.