Calcium, magnesium, strontium and carbonate are the basic foundation elements of coral skeletons.
All of these elements need to be available in balanced proportions for coral health and growth.
Red Sea'™s  KH/ALKALINITY  is a complex of carbonate and other buffers present in seawater that maintain proper alkalinity and pH, and is part of Red Sea'™s complete Reef Care program.
1ml will raise the Alk level of 100 litres (25 gal) by 0.036 meq/l (0.1dKH)