Sumps

[bertoni]

A sump is an auxiliary tank primarily used to hold equipment. Typically, it houses a protein skimmer, heaters, and a return pump that pushes water back up to the display tank. In addition, a portion of the sump can be used as a refugium. This illustration should help visualize how a sump works:



Using a sump helps keep the water level in the display constant. A sump also can hold other equipment, and often is a good place to dose various products into the system. The sump also can act as a reserve to help keep the water level in the display tank constant.

Another benefit is that the overflow will help keep the surface of the aquarium cleaner, by skimming off the floating layer that commonly appears. This picture shows an overflow in action: