A deep sand bed isHow Sand Beds REALLY work
by Ronald L Shimek, PhD, in Reefkeeping online magazine a filtration method used in some

saltwater aquarium A marine aquarium is an aquarium that keeps marine plants and animals in a contained environment. Marine aquaria are further subdivided by hobbyists into fish only (FO), fish only with live rock (FOWLR), and reef aquaria. Fish only tanks often s ...

s and some

freshwater aquarium A freshwater aquarium is a receptacle that holds one or more freshwater aquatic organisms for decorative, pet-keeping, or research purposes. Modern aquariums are most often made from transparent glass or acrylic glass. Typical inhabitants inclu ...

s. A deep sand bed, similar to the Berlin Method, is designed to cultivate

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: * Anaerobic adhesive, a bonding a ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

in the bottom layers of

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class o ...

, converting nitrate to

nitrogen gas Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh ...

to remove toxic nitrates.

Operation

A deep sand bed is commonly defined as a bed of fine sand with a minimum depth of four to six inches which ensures that a portion of the sand at the bottom will not be exposed to significant circulation of water. An established deep sand bed consists of sand populated with bacteria, algae and other marine organisms such as worms, crabs, snails and stars. The creatures burrow and overturn the top two to three inches of sand in search of food, which causes water to circulate deeper in the sand than it would if the creatures were not present. Deep sand beds may be made of a variety of materials, but typically fine or "superfine" sand is used, with a grain size between 1 mm and 0.05 mm. A larger particle size increases circulation, which in turn requires greater depth to establish anaerobic areas. Larger particles can also inhibit the burrowing of small animals, which would limit circulation into the bed. Additionally, larger particles (2 mm or larger) are prone to detritus accumulation, which necessitates periodic siphon cleaning.

References

Fishkeeping Aquariums {{fishkeeping-stub

Operation

See also

References