QANVEE Fluidized Moving Bed Filter Bubble Bio Media Reactor for Aquarium Fish Tank with Air Stone and Sponge Filter. Features & details Self Cleaning Filter Media constantly moving around and rub against each other only letting the strongest nitrifying bacterla survive Simply Hook up to an Air Pump and getting all the benefits of oxygen in the water and a super charged biofilter. Oxygen Rich Water combined with strong nitrifying bacterla handle large amounts of ammonia and nitrite compare to other type of filter Easy to Remove Intake Sponge provides additional physical filteration Comes with Enough Media similiar to K1 micro floats at first and starts tumbling in a few days