Product Description TetraPond GreenFree UV Clarifier works to keep your pond clean, clear, and free of unsightly green algae. These dependable clarifiers use ultraviolet light to destroy suspended green algae. As algae are pumped into the clarifier, they are exposed to ultraviolet light that destroys the reproductive ability of single-celled algae. The dead algae are then pumped out of the TetraPond GreenFree UV Clarifier, where they clump and are removed by your pond's filtration system. Removes heavy algae blooms (usually within 8 days) and keeps the pond algae-free long-term. TetraPond GreenFree UV Clarifier is durable, easy to conceal and installs in minutes. Comes with a high-efficiency bulb for up to 11 months of continuous operation and a high-clarity quartz glass tube. A viewing window makes it easy to ensure the UV bulb is working. Includes ¾ inch, 1 inch and 1 ¼ inch ID tubing adapters, as well as a 15 foot power cord. UL Listed. Features a 3-year limited warranty – see product packaging for details. Replacement bulbs available – replace every pond season (the bulb may continue to glow, but its effectiveness in killing algae diminishes). Available in four sizes: For ponds up to 660 gallons, up to 1,800 gallons, up to 4,400 gallons and up to 8,800 gallons. Since 1951, Tetra has developed the world’s most comprehensive body of fish food knowledge, and fishkeeping enthusiasts have looked to the brand for products and solutions that add ease and beauty to their home. Whether you're an experienced hobbyist or just starting out, Tetra has everything you need – from a large variety of quality fish food and innovative equipment to test kits and decor. Amazon.com TetraPond GreenFree UV Clarifiers Keep Your Pond Clear and Clean 15 foot power cord makes placing your UV Clarifier easy TetraPond GreenFree UV Clarifiers work to keep your pond clean, clear, and free of green algae. These dependable clarifiers use ultraviolet light to destroy suspended green algae. As algae are pumped into the Clarifier they are exposed to Ultra-Violet light that destroys the reproductive ability of single celled algae. The dead algae is then pumped out of the Clarifier where it clumps and is removed by your tank’s filtration system. Tetra UV Clarifiers can typically remove heavy algae blooms within five days and keep your pond algae-free long term. GreenFree UV Clarifiers are easy to conceal, durable, install in minutes, and feature a 3-year limited warranty. The UV clarifier can significantly improve water clarity ComponentsPL-S UV bulb: Provides 11 months of continuous operationHigh clarity quartz tubeStainless steel insert: Reflective surface increases UV exposure. Prevents internal UV degradation of plastic housing.Quick release couplingsTransparent fittings allow lamp-on checkMounting bracketsHow it WorksPond water containing single-cell algae is pumped into clarifier.Reflective stainless steel surface increases UV exposure.Ultra-violet light destroys single-cell algae’s ability to reproduce.Single-cell algae dies, clumps, and is removed by filtration.Long-Lasting Replacement BulbsTetraPond UV Bulbs should be replaced every 2 seasons or 11-months for maximum efficiency. UV Clarifier For Ponds Up to: Bulb Replacement 5 Watt 660 Gallons TetraPond 5 Watt Bulb 9 Watt 1800 Gallons TetraPond 9 Watt Bulb 18 Watt 4400 Gallons TetraPond 18 Watt Bulb 36 Watt 8800 Gallons TetraPond 36 Watt BulbMore Great Pond Products Koi Vibrance, Goldfish Multi Mix, Pond Sticks, Pond Flakes, Vacation Food 5 watt, 9 watt, 18 watt, 36 watt AquaSafe, Filter Starter, Water Clarifier, KoiVital, Sludge Reducer, Algae Control Water Garden Pump, ClearChoice BioFilter, BioActive Pressure Filter, Flat Box Filter, Waterfall Filter