Aquaforest TestPro Magnesium is designed to quickly measure the concentration of Magnesium (Mg) in marine water. Magnesium plays an important role in many biological processes e.g. takes part in the construction of hard corals calcium carbonate skeleton. Due to its unique chemical properties it has significant impact on seawater buffering capacity and also prevents excessive precipitation of calcium carbonate on aquarium equipment. Adequate level of Magnesium is crucial in maintaining proper Calcium and Alkalinity balance in reef aquaria. Mg levels should be analysed regularly together with other critical water parameters like Calcium and Alkalinity. The concentration of Magnesium in natural seawater is between 1260-1460 mg/l (ppm). Test Kit contains sufficient reagents to perform approx. 55-60 separate tests within that range.