Revolutionary 5-stage power filter takes aquarium filtration to a new level of convenience. AquaTop PFUV Elite Series Power Filter with UV allows hobbyists of all skill levels to enjoy the extreme convenience of a hang-on-back filter PLUS UV sterilization AND surface skimming without additional equipment or complicated plumbing. Great for use with freshwater or marine aquariums and an invaluable addition to any quarantine regimen. AquaTop PFUV Elite Series Power Filter with UV features an internal UV Sterilizer to help control unwanted green water algae blooms and to eradicate free-floating parasites such as Ich. Self-adjusting, built-in surface skimmer removes surface debris and oil to maximize gas exchange essential for maintaining optimal oxygen levels.