It is impossible to maintain a healthy, vibrant marine aquarium without also maintaining the proper levels of calcium and alkalinity. Fritz RPM Calcium Buffer System allows aquarists to maintain these two critical components in their proper ionic balance. Unlike other similar products, Fritz RPM Calcium Buffer System does not contain unmeasured and unnecessary ions and metals, which unchecked can lead to toxicity in the aquarium. Part 1 is formulated to provide the highest purity carbonate alkalinity, and when used in conjunction with Part 2, along with regular water changes with a high quality salt, will provide the correct ionic balance necessary for healthy and beautiful fish, corals and invertebrates. 000 dKH Ingredients: Deionized water, Sodium bicarbonate, Sodium carbonate.