text: This basic concept is more correctly known as an aspirating skimmer, since some skimmer designs using an aspirator do not use a "Pin-Wheel"/"Adrian-Wheel" or "Needle-Wheel". "Pin-Wheel"/"Adrian-Wheel" describes the look of an impeller that consists of a disk with pins mounted perpendicular (90°) to the disc and parallel to the rotor. "Needle-Wheel" describes the look of an impeller that consists of a series of pins projecting out perpendicular to the rotor from a central axis.  "Mesh-Wheel" describes the look of an impeller that consists of a mesh material attached to a plate or central axis on the rotor. The purpose of these modified impellers is to chop or shred the air that is introduced via an air aspirator apparatus or external air pump into very fine bubbles. The Mesh-Wheel design provides excellent results in the short term because of its ability to create fine bubbles with its thin cutting surfaces, but its propensity for clogging makes it an unreliable design.
  The air aspirator differs from the venturi by the positioning of the water pump. With a venturi, the water is pushed through the unit, creating a vacuum to draw in air. With an air aspirator, the water is pulled through the unit, creating a vacuum to draw in air. These terms, however, are often incorrectly interchanged. 
  This style of protein skimmer has become very popular with public aquariums and is believed to be the most popular type of skimmer used with residential reef aquariums today. It has been particularly successful in smaller aquariums due to its usually compact size, ease of set up and use, and quiet operation. Since the pump is pushing a mixture of air and water, the power required to turn the rotor can be decreased and may result in a lower power requirement for that pump vs. the same pump with a different impeller when it is only pumping water.