An elementary substance; a metal which combined with oxygen forms lime. It is of a pale yellow color, tenacious, and malleable. It is a member of the alkaline earth group of elements. Atomic weight 40. Symbol Ca.
A chemical found in lime, chalk and limestone which are used to neutralize soil acidity. Essential for crop growth. Also essential together with phosphorus for healthy teeth and bones in animals.
A chemical element important for bone formation
best known for its role in bone structure and repair. It is essential for proper bone development, muscle function, and reproduction. Calcium makes up about 35% of the horse's bone structure. It is also involved in other functions - including cardiac muscle contraction, cell membrane integrity, glandular secretion, temperature regulation, and blood clotting mechanisms.
A necessary element used by salt-water corals and other organisms for their calcium carbonate skeleton or shell. A high calcium concentration is associated with the hardness of water. See carbonate hardness.
One of the major plant nutrients, it forms the structural part of the walls of plant cells. It is generally applied to soils in the form of calcium carbonate (limestone) or as an ingredient in commercial fertilizers.
In the form of calcium silicide acts as a deoxidizer and degasifier when added to steel. Recent developments have found that carbon and alloy steels modified with small amounts of calcium show improved machinability and longer tool life. Transverse ductility and toughness are also enhanced.
Aluminium - killed steel, while in the ladle prior to being cast, often has calcium, in the form of calcium silicide, injected into the liquid bath. The addition of calcium lowers the level of the remaining oxygen and sulphur contents of the steel and modifies the residual inclusion composition and shape. This has the effect of improving the cleanliness, castability, machinability and of reducing the anisotropy of toughness and ductility of the steel.
chloride CaCl2. This is a form of calcium that may be added to reef tanks to maintain the calcium level. However, kalkwasser (calcium hydroxide) is preferred, as adding kalkwasser does not upset the alkalinity or ionic balance the way calcium chloride can.
Short for calcium chloride-water solution used to fill tractor tires for ballast.
A mineral that is the major building block of corals and other calcareous organisms. In a reef tank, calcium levels should be maintained between 380 and 480 mg/l. Calcium levels can be maintained through regular water changes, by using calcium additives, or through the use of kalkwasser.