Encap 10610-24 Fast Acting Gypsum with Ast, 30 lbsLoosens clay soils and helps improve water and air penetration. Combined with patented AST polymer formulation. It is eight times more effective at retaining calcium and helps repair the effects of animal urine spots. 1 application lasts all season. 30 lb 5,000 sq. ft. coverage Gypsum plus ast High quality Calcium & sulfur Combined with patented AST polymer formulation Up to 8 times faster than typical gypsum Loosens crusty soil Repairs winter salt