Brightwell Aquatics Balanced Calcium & Alkalinity Part B (Alkalinity) System Powder The alkalinity-bearing component of a two-part method for dosing calcium and carbonates (the substances largely responsible for increasing alkalinity (buffering capacity)) in the same ratio as that found in natural seawater Benefits reef-building organisms such as corals, clams, calcareous algae, etc. Simplifies calcium and alkalinity maintenance; economical for particularly large systems