Reef buffer is intended primarily for use in a reef system where the maintenance of a pH of 8.3 is often difficult. When used as directed reef buffer will raise the pH of your reef system to 8.3 without fear of accidentally overshooting the pH to a dangerous level. Reef buffer will also raise carbonate alkalinity. Reef buffer is a blended product and is not just sodium carbonate. Reef Builder should be used to raise alkalinity when pH is not a problem. Use Sachem's Multitest: marine pH & alkalinity to check pH and total alkalinity.