OASE 706759564557 Vitronic 18 UV Clarifier for Pond Vitronic 18-36W are simple, yet versatile UV Clarifiers designed to operate with all filter systems, although best suited for the BioSmart 5000-10000 filters. Easily integrated into an existing or new pond system, Vitronic UV Clarifiers clean the green out of water. High quality UVC bulbs guarantee a long service life, and a constant effective irradiation capacity. Safely confirm that the UVC is working with clear tubing adaptors and the visual inspection window at the top of the filter. Quick release provides easy UV unit opening and closing for easy bulb change and cleaning of the quartz glass.