DescriptionSpa Sanitizing Granules is sodium dichlor stabilized chlorine for shocking or super-chlorination of hot tub and pool water. Dichlor is also an ideal shock for occasional use with alternative sanitizers. Clears many water problems quickly and unlike other brands, dissolves fast to save time and effort. This maximum-strength dichlor is formulated for hot tubs with no scale forming minerals or insoluble fillers. You cannot buy better dichlor at any price. Maximum strength - 99% No insoluble fillers Quick-dissolving 2 lb. bottle Product notes: Active ingredient is sodium dichloro-s-triazinetrione dihydrate, 99%. Guaranteed to equal or outperform all other brands -- compare to Leisure Time Spa 56 Chlorinating Granules. Pre-dissolve by itself into plastic bucket of water before adding to spa.