When used with a biological filter, PondMAX UV Clarifiers will restore clarity and healthy conditions to your pond or aquarium. By treating the water which passes through with the UVC, algae and bacteria are destroyed to achieve crystal clear water within 14 days. Features a safety shut-off switch for bulb replacement. Features Robust UV Resistant Body Optional Bypass Port and Flow Regulator Valves Multi-Stepped Hosetail fittings for simple installation Built-in Mounting Bracket Clear Hosetail for UV Clarifier Operating Indicator Model Max Pond Size (No Fish/ Shaded) (Gal.) Max Pond Size (Fish/ Full Sun) (Gal.) Max Flow (GPH) Cord Length (FT.) PU09W, 9 Watt 2400 1200 1200 10’ PU18W, 18 Watt 4800 2400 2100 10’ PU36W, 36 Watt 9600 4800 3200 10’