Ornamental algae and invertebrates need calcium to build up their shell resp. calciferous skeleton. The calcium concentration in natural saltwater is about 400 - 450 mg/l. The same calcium level should be maintained in the aquarium by regular addition of
It does not affect the carbonate hardness or the pH value. Furthermore, it does not react with the important trace elements as, for example, calcium hydroxide (kalkwasser) does.