Pound-for-pound sponge filters are the most effective bioactive filters on the market. In combination with traditional media efficacy of this filter is incredible. Completely rinse out the the sponges in tap water and you will still have a fully viable bacterial colony in your biomedia.
Sponge filters provide both mechanical and biological filtration - Traps floating debris and protect your baby fish from being sucked up into the filter, aerobic bacteria colonize the sponge providing a bacterial substance to facilitate the nitrogen cycle.
 
Simply install an airline into the unit and turn on the air pump, great way to clean and oxygenate your tanks; Easy to clean: simply squeeze the sponges in tank water. Two sponges means more surface area for beneficial bacterial colonization and faster cycling, keep your fish tank crystal clear and clean.