CLR Pro SEP-4PRO Septic Treatment and Drain Care System, 1 Gallon Bottle Monthly bioactive treatment helps maintain septic systems with up to 1500 gallons and neutralize odors Suitable for use in drains, toilets, and RV tanks to help maintain free-flowing drains and neutralize odors Contains microorganisms that digest and help eliminate fat, oil, grease, and organic matter Stabilized formula deposits live active bacteria immediately into septic system to facilitate treatment EPA-approved to meet DfE Standard for Safer Products