Ultra-violet sterilization is a point-contact process of irradiation, and is commonly used to treat influent water in a variety of systems. It is used to treat aquarium systems, hatcheries and drinking waters. It is a proven solution to waterborne planktonic algae as well as other harmful pathogen problems commonly associated with aquatic recirculating systems such as, mammal/reptile bathing pools, fish/invertebrate exhibits, and fish culture systems. The efficacy of UV sterilization depends on: UV bulb wattage, age & cleanliness; distance between the bulb and the target organism; species and individual characteristics of the target organism.