Used for years in America, this is the No. 1 sump installed skimmer for all saltwater aquariums up to 1000 litres The T. 1000 classic uses the same patented Needle Wheel technology as the whole Aqua Medic Turboflotor skimmer family. The Needle Wheel rotates at 3.600 rpm in the pump housing, the air/water mixture is heavily agitated and the air bubbles are cut into micro bubbles for optimum skimming efficiency. The Needle Wheel pump draws water directly from the skimmer, mixes it with air and drives the mixture back into the skimmer. A great advantage of the skimmer is its aquarium water supply. Water flows directly to the skimmer as a bypass (approx. 250 gph) from the overflow of the aquarium, without the need for a pump. In this way, the flow rate can be easily adjusted with a valve. This means the whole power of the Needle Wheel pump is used to inject air. This water flow creates an extremely high turbulence in the lower part of the skimmer and ensures that a very high quantity of air (approx. 50 g.p.h) is injected. The upper part of the skimmer stays calm and leaves enough time for the bubbles to react with the organic wastes and form a stable dry foam, that is pushed into the conical shaped foam cup. Dimensions: The height of the skimmer is only 21 inches, so it will fit into the sump in most standard cabinets. Pump: the skimmer is designed to be used with the Rio 2100 power head pump. Why is the Needle Wheel superior to bladed impellers for air water mixture? In contrast to bladed impellers, the Needle Wheel does not cause noise problems or cavitation. Bladed impellers are very good for pumping water, but are not designed to pump an air/water mixtures. They create a pressure drop at the blade tip that creates supersaturation with nitrogen gas. This process is called cavitation and it may cause gas embolisms (gas bubble disease) in fish. Height: 55 cm, c. 22". Total width: 17 x 17 cm, c. 7" x 7".