Concentrated KH Buffer Supplement for All Marine Fish and Reef Aquaria Overview Highly-effective alkalinity(KH)-increasing (”buffer”) solution. Helps increase pH Stability in an aquarium by raising the alkalinity. Provides a source of carbonates, which make up the majority by weight of aragonite, the mineral secreted by reef-building organisms as skeletal material. Continued addition raises pH until 8.3 is reached, at which point the pH remains unchanged and the alkalinity alone increases. Over 50% stronger than most competing products. Free of phosphates, silicate, and organic material. Formulated by a marine scientist.