CLR Septic System Treatment is the ONLY septic system treatment to be partnered with the EPA s Safer Choice Program recognizing the product as a safer alternative to chemicals. With 7 treatments for systems up to 2000 gallons it works instantly can be used any time of day and its patented stabilization process allows for live active bacteria to be deposited into the septic system. Unlike competitors products this innovative formula does not contain detergents preservatives and inert carriers that the bacteria attach to in use. See more