Rid-x, 39.2 oz, professional septic tank system treatment, concentrated powder formula contains billions of 100% natural active bacteria & enzymes selected to effectively digest septic system waste, breaks down the solid organic waste that can accumulate in your septic tank, such as detergents, soaps, grease & paper, regularly will help keep the bacteria population consistently high throughout the year, use monthly along with regular pumping, 39.2 oz 4 monthly doses for tanks up to 1500 gallons.