An Aquarium Sump is a separate piece of filtration equipment much like another aquarium that is plumbed into the filtration display tank. They are frequently used in saltwater aquariums and reef tanks because the additional filtration equipment needed is meant to be placed in the sump or is plumbed through the sump in some way. The sump is normally placed inside the tank cabinet/stand and other times they are plumped to a separate fish room for better accessibility.
Water enters the sump into a dedicated section where the water will then flow over into Section 1.
Section 1 is the configurable interchangeable plate area allowing for filter sock and/or foam block mechanical filtration. This area is covered with a lid to prevent water splashing and reduce noise. Water then flows out the bottom of Section 1 into Section 2.
Section 2 is typically where the protein skimmer is located. Water then flows through the ‘Trigger Symbol’ cutout into Section 3.
Section 3 is the refugium section. The water then flows over the adjustable water level baffle through 2 perforated platforms and under the last baffle into Section 3. The top perforated platform comes with a foam block filter and the bottom one is open to use for several different filtration methods (bag of carbon, bio balls, bio media, rubble rock, etc.).
Section 4 is the return section where the return pump will sit, pumping water back to the display tank.