The AquaClear 70 Power Filter features a unique multi-stage filtration system that provides complete mechanical, chemical and biological filtration for superior water quality. The Power Filter has a filtration volume up to 7 times larger than similar filters. It also enables superior contact time with the filter media. The filter maintains Beneficial bacteria creating a stress-free environment for aquarium inhabitants and maintaining pure aquarium water. Its unique waterfall design allows filtered water to return to the tank silently, gently breaking surface tension and creating beneficial oxygenation.