An UV units uses Utltra ultraviolet light to help improve the quality of water in either a freshwater or marine aquariums. They help reduce and control alage and can help control bacteria and pathogen levels in the aquarium.
UV units need to be inspected regularly and have their UV bulb changed approximately every 6 months after continuous use. Unless this happens the UVC output from the lamp falls off until it is no longer sufficient to give effective bacterial control.
