Magnesium Chloride is an ideal, environmentally sensitive product to improve the appearance and playability of sprinkler-irrigated Har-Tru tennis courts. Like Calcium Chloride, Magnesium Chloride draws moisture from the atmosphere into the Har-Tru court surface to keep it moist, green and playable. Unlike Calcium Chloride, Magnesium Chloride is non-corrosive to metals. Magnesium Chloride is most frequently applied before tennis tournaments so that the courts can be used for an extended period of time without watering. It can also be used to offset drought or dry conditions. Available in 50 lb. bags.