Seachem Reef Fusion 1 and Reef Fusion 2 are the foundation of a system formulated to provide the essentials for the reef aquarium. Reef Fusion 1 provides calcium, while Reef Fusion 2 provides alkalinity. When used together, the Reef Fusion system will maintain calcium and alkalinity levels.Reef Fusion 1 provides not only 100,000 mg/L of ionic calcium, but also includes biologically appropriate levels of magnesium, strontium, boron, iron, manganese, and molybdenum.