The Oase Vitronic UVC Clarifier range are highly effective against suspended green water algae, bacteria and germs. The Oase Vitronic UVC can be combined with almost any pond filter system to provide peace of mind with clear water quality. The Oase Vitronic is a top quality UVC which will help keep your pond water clear. The Vitronic UVC works by making the small particles of algae that cause green water clump together, so that they can be removed by your filter system. Oase UVC replacement bulbs have a service life of 8000 operating hours. Replacement bulbs will perform like new, and will continue to meet the requirements of a Clear Water guarentee. When replacing your Vitronic bulb, please ensure that a Philips bulb is use, this will ensure that the quartz sleeve does not shatter or crack. Please note that as an outdoor electrical item, this product is not supplied with a plug.