Concentrated KH aquarium buffer supplement is safe for all marine fish and reefs. Helps increase pH stability in your aquarium by raising alkalinity. Alkalin 8.3 provides a strong source of carbonates and will raise pH to 8.3 if continually added. Once 8.3 is reached; pH will remain unchanged and the alkalinity alone increases. Over 50% stronger than other products and formulated by a marine biologist.