Sunterra Pond UV Bio-Filter 1000 Gallons, Black Features Ultra-violet Light Filtration that Eliminates Algae that Survive Normal Filtration Creating a Cleaner and Healthier Pond Dual Filtration System to Provide a Clearer and Healthier Pond or Water Garden Cleans Ponds up to 1000 Gallons Recommended for use with Pond Pumps Capable of Pumping between 850 to 1250 Gallons of Water Per Hour Two Year Limited Warranty