fishkeeping Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. It is a practice that encompasses the art of maintaining one's own aquatic ecosystem, featuring a lot of variety with various w ...

, a sump is an accessory

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

tank in which mechanical equipment is kept. A remote sump allows for a clutter-free display tank. It is found mainly in a

reef aquarium A reef aquarium or reef tank is a marine aquarium that prominently displays live corals and other marine invertebrates as well as fish that play a role in maintaining the tropical coral reef environment. A reef aquarium requires appropriately i ...

or marine aquarium. The sump sits below the main tank, and is used as a filter, as well as a holding place for unsightly, miscellaneous equipment such as

protein skimmer A protein skimmer or foam fractionator is a device used to remove organic compounds such as food and waste particles from water. It is most commonly used in commercial applications like municipal water treatment facilities, public aquariums, and ...

s, calcium reactors, and

heaters A heater is an appliance whose purpose is to generate heat for a building. Heater or Heaters may also refer to: Science, technology and engineering * Central heating, a system used to heat an entire building Devices * Aquarium heater, in fishkee ...

. The main advantage of having a sump plumbed into an aquarium is the increase of water volume in the system, making it more stable and less prone to fluctuations of pH and

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

, and also mitigating the effects of nutrient buildup or the unintentional introduction of foreign substances. In addition, some sumps have a compartment that can be converted into a refugium, helping to filter out excess nutrients such as

nitrate Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...

s. A sump can also improve aeration of the water in the aquarium. Water movement between the sump and the display tank helps with gas exchange between the water and air. Increased

dissolved oxygen Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can ...

is beneficial to fish and can also aid in avoiding ''

Cyanobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...

'' outbreaks.The Benefits of an Aquarium Sump
by Jeff Hesketh

References

Fishkeeping Aquariums {{fishkeeping-stub