How does a sponge filter work?

[theotheragentm]

I have a 10-gallon tank with Dwarf Crayfish. It has an AquaClear filter on it currently. I've seen a lot of smaller tanks with shrimp using sponge filters. Is there a reason I would want to use one? I don't know if someone told me this but I was under the assumption that they disrupt the water less. How do these work?

Thanks in advance for your help.

[rkilling1]

The search feature works great for these kinds of questions.

http://www.aquariumadvice.com/viewtopic.php?t=99093

[Ziggy953]

I'm assuming you are talking about an air driven sponge filter.

An air line pushes air into a chamber usually filled with carbon and the air bubbles coming up and out of the filter draw water into the carbon through the sponge. It makes a gentle current that washes the water through the filter.

[gheitman]

A sponge filter is a very simple device that uses air pumped from outside the tank to draw water through one or more sponges. The sponge cells provide an excellent medium for the growth of bacteria that break down fish waste. Sponge filters typically do not provide chemical or mechanical filtration but work very well in quarantine/hospital tanks (because they usually don't contain charcoal which can break down medications) or fry rearing tanks (the sponge surface serves as a good location for fry to feed on micro-organisms and there is no danger of fry being sucked up into a filter). I have sponge filters on 7 of my tanks (all 20 gallons or less) and like the simplicity, low cost and ease of maintenance.