The HI772 Checker®HC (Handheld Colorimeter) provides a simple, accurate, and cost-effective way to measure alkalinity in degrees of carbonate hardness, commonly abbreviated as dKH. Critical to marine environments, alkalinity not only provides the carbonate ion required for calcium carbonate skeletal regeneration of coral reefs, but it also acts as a pH buffer against large changes in acidity. Designed as a more accurate alternative to chemical test kits, the HI772 provides quick, accurate results in a few easy steps.