We here at Angry Fish use a wide variety of filtration on all of the different tanks that house our fish. No matter what we use or the size of the tank, one thing remains. We will always have a minimum of two sponge filters in each and every tank. This is the best for Biofiltration. Also we tend to complete this mini Ecosystem with a variety of different plecos. Mainly of the Bristlenos Genus. They will feed off of the sponges and keep them clean for the most part. Oxygen and water polishing are a plus for any ecosystem.