Brightwell Aquatics Reef Code B - Balanced Calcium & Alkalinity System - Part B (Alk.) 500ml / 17oz The carbonate-bearing component of a two-part method for dosing calcium and carbonates (the substanc Ionically-balanced with respect to natural seawater concentrations of calcium and carbonates when us Benefits reef-building organisms such as corals, clams, calcareous algae, etc Simplifies calcium and alkalinity maintenance Stronger than most competing products