Solution Grade Gypsum, Calcium Sulfate Dihydrate, is a very fine, free-flowing, odorless, tasteless white powder produced by fine-grinding and air separating a select grade of soluble high-purity white gypsum.  Soluble gypsum is a white, high purity, finely ground calcium sulfate dihydrate which is used to improve soils in turfgrass and agricultural applications. This solution grade gypsum is readily dissolved in water(soluble) and is usually delivered through an existing irrigation system to condition calcium deficient soils for enhanced plant development.