Cleans sluggish septic tanks, cesspools, drywells, and drain fields. Contains fast-acting bacteria cultures that act quickly to restore operating efficiency. Should be applied to any septic tank or cesspool when sluggishness is first noticed. Allow 1 week for system to return to normalcy, then apply Roebic K37 or K47 to prevent future clogging. Each 1/2 gallon bottle treats 1000 gallon tanks.