From a large free-form outdoor pond to an intimate patio tub garden to a unique indoor waterscape, the beauty of exotic water plants, colorful swimming fish, the delightful rush of moving water can be created as large or as small as you like. Pondliner.com provides a variety of fish pond filters. OASE pond filters are designed to eliminate cloudy, dirty pond water and algae growth by converting ammonia, produced by pond fish waste, dead plants, etc., into nitrite and then into relatively harmless nitrate using a natural process. OASE pond filters are designed to be used outside of the water garden. OASE makes a filter to suit your needs, whether it be a waterfall, water garden, koi pond, garden pond or small lake.