For fresh and saltwater systems up to 180 gallons, meet the CAF-180! Simple, economical and so easy to install, the CAF-180 offers excellent filtration while oxygenating the water. You simply can't beat the price and performance of the CAF Series which can be used as a stand-alone filter, a breeding filter or for extra biological filtration in heavily stocked aquariums. Even add it to your external or top filters as a pre-filtration unit! Another neat feature of the CAF Series is the airlift system for excellent biochemical filtration and pleasantly quiet operation.