Pondmaster UV Clarifier/Sterilizer (40 Watt) – A powerful UV light unit for larger ponds up to about 6,000 gallons that helps maintain crystal-clear water. It can be used either submersed in the pond or installed inline. The 40W ultraviolet lamp eliminates green water algae and can even help control bacteria and protozoa, improving overall water quality. It features a glowing halo ring indicator to show the UV is functioning and uses a long-lasting bulb (approximately 9,000 hours) to provide continuous, chemical-free water clarification.