The DYMAX IQ skimmer is an air driven mini skimmer designed not only for IQ5 but also for most mini marine aquarium. The wooden air stone diffuses the air into very small air bubbles, while the air bubbles rise through the water that remove protein waste from the water. The waste foam is produced above the water level and then rises through the foam tube into the collection cup. In this way, waste particles and toxic compounds are totally removed from the aquarium, which is the essential difference between this and other forms of biological filtration. Comes with adjustable air flow valve. Please Note: Air pump is not included.