OASE BioSmart 10000 Pond Filter Innovative Flow-Through filter design with biological and mechanical filtration provides maximum oxygenation. BioSmart 10000 is suitable for ponds up to 10,000 gallons (with no fish). High-surface area filter foams provide exceptional biological filtration capability. Distinct filter zones promote the settlement of a variety of beneficial bacterial responsible for different phases of the nitrogen cycle, which increases the conversion of harmful ammonia in your pond . Advance features include the built-in cleaning indicator notifies you when the filter needs cleaned and water temperature display tells you the water temperature at all times.