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 Seachem's MultiTest: Marine pH & Alkalinity™ to check pH and total alkalinity. 500 g treats 16,000 L (4,000 gallons).