Roebic’s easy to use K-37 contains patented ROETECH bacteria that keeps your septic system running smoothly. Prevents the clogging of inlet and outlets that can lead to unpleasant odors and overflowing receptacles. K-37 works in both your septic tank and drain fields. Economical and safe for all plumbing. Treats a 500-gallon septic tank. Digests paper. Safe for the environment. Certified biodegradable. Easy to use.