Sponge Filter?

[sted]

how do they work?

 

[Ashley1991]

http/aqualandpetsplus.com/Misc%20Sponge%20Filters.htm

that will pretty much cover everything to do with sponge filters i made one myself and it works a treat

mine is just a big piece of sponge with a tube in it at the bottom of the tube is a air stone the bubbles form that draw the water in from the outside (something to do with pressure) and then the bubbles and water come out the top

ash

edit: that was just a quick google search the brought that up im sure there are better sites too

edit edit: they are really easy to make yourself and you can make them as big as you want there are lots of guides if you do a google search