The Dymax Power Hang On filter is an overflow style filtration system that make in water from the aquarium and flow out to the water surface. creating a current throughout the entire aquarium. This bringing more water molecules to the water surface when physical get contact with the atmosphere. enabling them to release carbon dioxide and create sufficient oxygen more efficiently. The Dymax Power Hook On Filter is design to the benefit of removing aquarium waste both mechanically and biologically. This producing debris free and clear water to the aquarium.