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 phosphate, silicate, and organic material, Formulated by a marine scientist, Liquid, 500-ml, SKU: RYLHC1046