·· Flow Control: Simply shift the patented Flow Adjustment Control at the the intake siphon. When the Flow Adjustment Control is at its greatest blockage, AquaClear's input and exhaust volumes are approximately a third of its maximum capacity. The AquaClear 50 Power Filter provides mechanical, chemical, and biological filtration through its multi-stage filtration system. Filtration volume is up to 7 times larger than comparable filters. Its unique design filters aquarium water through a natural and silent waterfall. The patented flow control feature allows for customized filter performance. The filter preserves beneficial bacteria, creating a stress free environment for aquarium inhabitants and maintains clear aquarium water. Installation and maintenance are quick, easy, and convenient. The filter comes equipped with AquaClear Foam, Activated Carbon, and BioMax. In addition, AquaClear delivers an entire line of media including Zeo-Carb and Ammonia Remover exclusively designed for the AquaClear Power Filter. The AquaClear 50 Power Filter is ideal for use in 20-50 US gallon (76-190L) aquariums.