koi5000Oase BioSmart 5000 Pond Filter (56929) The Oase BioSmart 5000 Pond Filter is desned to eliminate cloudy, dirty pond water and algae growth by converting ammonia, produced byKoi fish add a unique and beautiful look to your pond. We offer a range of different koi breeds to suit everyone’s needs in South Africa. Ranging from small to large fish, we got you covered!