Quickly and easily connected to most canister filter setups, the Fluval UVC In-Line Clarifier eliminates suspended bacteria and algae for a clear and healthy aquarium. Fluval CCFL technology attacks cloudy and green water by applying powerful, DNA-destroying UVC light emissions. This natural process is chemical-free and will not affect beneficial, surface-dwelling bacterial colonies that are already established. With its distinctive compact design, the unit fits neatly within aquarium cabinetry without cluttering existing filtration systems. A chemical-free and maintenance-free way to purify water that eradicates suspended bacteria and algae in the water column that contribute to cloudy and green water, respectively Helps prevent the growth of cyanobacteria that often smothers and destroys aquatic plants and does not harm beneficial, surface-dwelling bacteria CCFL (Cold Cathode Fluorescent Light) technology runs cooler than traditional UVC bulbs to last up to 30,000 hours (3X longer) Quickly connects in-line to all canister filter hosing with an internal diameter of 5/8” (or 16mm), including all Fluval 07 and 06 Series filters For use in freshwater, saltwater and even turtle aquariums where algae is often present I BOUGHT IT FOR $100. It’s brand new never been opened. See less