UV Sterilzers are low pressure mercury vapor lamps which produce the UVC dose necessary for microorganism's eradication. Ultraviolet light is generated by an electrical discharge through low pressure inert gases and mercury vapor. These rays will distroy 80-90 % of all bacteria in your tub. Not only will this save you money on chemicals, it will reduce the time you spend maintaining your chemicals. UV lamps last up to 13000 hours and are virtually maintenance free. They install inside the spa skirt so they are also out of site. For more information, stop by The Comfort Zone showroom in Port Alberni, the valley's only hot tub showroom