TetraPond GreenFree UV Clarifier works to keep your pond clean and free of unsightly green algae. These dependable clarifiers use ultraviolet light to destroy suspended green algae. Comes with a high-efficiency bulb for up to 11 months of continuous operation and a high-clarity quartz glass tube. Includes ? inch 1 inch and 1 ? 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. 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.Ultraviolet clarifier controls heavy algae blooms in ponds and water gardens and keeps water clean and green-free.