Dynamic - Reef Aquarium Core Builder is the building blocks for your reef aquarium and live corals. Alkalinity, Calcium and Magnesium are vital supplements for coral reef aquariums. This high purity, pharmaceutical grade Alkalinity, Calcium and Magnesium work together to stabilize these vital parameters and provide the proper components to create a stable, thriving, growing reef aquarium. Dynamic - Reef Aquarium Core Builder simplifies dosing these vital supplements necessary for healthy coral and invertebrate growth.