Is a sponge a filter feeders?

A simple, but effective form of filtration. A current of air is passed through the center of a sponge such that as the air rises, it draws water into the sponge, thereby filtering the water. Sponge filters are very easy to clean (rinse and squeeze in water) and last years. Plus, baby fish don't get trapped in them like so many other filters. There are several styles of sponge filters ranging from square sponges to long cylinders to tall cylinders.