Description
A sponge filter uses bubbles of air from an external air pump, or an integral water pump to draw water through the sponge. As water is drawn out through the lift tube or pump, it is replaced by water entering the sponge. The sponge is a mechanical filter and the surface of all the bubbles or pockets in the sponge provide a bed for the bacteria of a biological filter. The bacteria help to break down harmful waste (ammonia and nitrite). Sponge filters provide both mechanical and biological filtrat
