250G Specially formulated mixture of carbonates, sulfates, and chlorides of sodium, magnesium, calcium and potassium with all necessary minor and trace minerals to approximate Rift Lake water chemistry. Designed to provide natural water chemistry to African cichlids and other rift lake fishes without significantly raising pH. Compatible with and designed for use with A F Cichlid Buffer for pH control and A F Cichlid Rift Lake Trace Elements. Contains no phosphates, nitrates, silicates or organics to pollute the system. (Note: competing products usually contain very high levels of silicates which encourage diatom (algae) growth on the tank walls! This product does not!) A F Cichlid Chemistry will also benefit most American cichlids whose waters are hard and have high pH's above 7.8!