Add Granular K-37 Septic Tank Treatment Concentrate to your septic tank every other month and have peace of mind that your septic system is working properly. K-37 is formulated with RoeTech, our exclusive bacteria to break down sewage waste. K-37 Granular prevents the clogging of inlets and outlets that can lead to unpleasant odors and overflowing receptacles. Easy to use, just pour 6 oz. into the toilet bowl and flush twice. There are 2 applications per bag. Each application treats a 1500-gallon septic tank.