For 50 year, fishkeeping enthusiasts have looked to the Tetra name 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. 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. UL listed. 15 foot power cord.