Sunterra 300207 Pond UV Bio-Filter 2000 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 2000 Gallons Recommended for use with Pond Pumps Capable of Pumping between 1,250 to 2,000 Gallons of Water Per Hour Two Year Limited Warranty