TARARIUM Fish Tank Filter Small Pond Filter for 100-200 Gal. Tank Crystal 420GPH Biochemical Filtration Powerful Submersible Water Pump Large Aquarium Accessories Air Supply[Biochemical Filtration] Double depth biochemical filtration. Filter Sponge effectively cultivate beneficial bacteria like nitrifying bacteria. Filters fecal food residue. Make your Cloudy Milky fish tank CRYSTAL CLEAR.. [Powerful 420GPH] Powerful water flow adds vitality to the water in your aquarium. Creates waves on the water surface. Filter 420 gallons of water per hour. [Perfect for Large Tank Small Pond] This aquarium filter is suitable for