Alkalinity is one of the most important
parameters to measure in aquariums. It
helps to maintain a stable pH, an important
factor for most aquatic life. In seawater,
bicarbonate is the largest contributor to
alkalinity and is a critical element needed for
healthy corals. Corals need bicarbonate and
carbonate available to form their skeletons.
Without an adequate level, healthy coral
growth is not possible. Since bicarbonate
levels can be di#cult to determine, total
alkalinity is measured instead. The alkalinity
of natural seawater is typically 125 ppm
CaCO3 (equivalent to 7 degrees of carbonate
hardness, or dKH). In saltwater aquariums,
typical alkalinity values can range from
125 to 200 ppm CaCO3 (7 to 11.2 dKH).
