For sluggish septic tanks, cesspools, drywells and drain fields. Acts quickly to restore operating efficiency. Apply when sluggishness is first noticed, or use when system has not been used for a long period of time. Use approx. 1 litre per 1750 litres capacity - 10 days after using K57, follow up with K37 for septic tanks or K47 for cesspools. Watch Roebic NRA 2010 video on Vimeo.