The ArcadiaUltra Clear UVC Lamp eliminates suspended algae in ponds to provide crystal clear pond water. It is also suitable for aquarium clarifiers and sterilizers. Green water and algae problems can be a nuisance, especially during the summer month. Using a UV and replacing the lamp every six months can resolve these issues, Ultra Violet light is used to clump together the floating single algae cells which makes it easier for the pond filter to remove. Thiscompact lamp will remain effective for 12 months.