Instructions: Fill clean litter box with 3 to 4 inches of Scoop Away clumping cat litter. For best results, do not mix Scoop Away litter with non–clumping cat litter. Remove clumps and solids daily, and dispose in trash. Do not flush. The rest of the litter stays fresh. Top off litter box to maintain to a 3 to 4 inch depth for optimal performance.