Aquatop"s versatile PH Series Powerheads provide great water movement and can be used for several types of applications. Super quiet and made of durable plastic, the powerhead can be used to increase water flow within your aquarium, eliminating low flow "dead spots" that otherwise would accumulate fish waste and debris. Improved water circulation helps maintain good water quality and overall tank health. Also includes an option venturi valve that helps add dissolved oxygen to the water. PH Powerheads can also be used to power undergravel filters or external appliances like ultraviolet sterilizers . Comes with suction cup bracket for secure attachment to glass and features a rotational output that allows you to direct the flow of water. The PH-8 model uses 8w and has a flow rate of 158 gph.