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