2 Uses in 1: CCLS toilet bowl cleaner tablets help clean the entire tank and system of the toilet and septic tank. Each flush of this blue toilet bowl tablet creates a protection on the side wall of the toilet bowl and drain, preventing the adhesion of stains from waste as well as providing the bacteria needed to maintain a healthy septic system. How It Works: The bacteria present produce enzymes that break down organic solid materials into food for bacteria. The bacteria digest this material and use the food to multiply and produce enzymes. This cycle continues until the waste has been completely digested, leaving the area free of solids, free-flowing, and odor-free. Chemical Free: Formulated from naturally occurring organisms. Non-toxic, non-hazardous, non-corrosive, non-combustible. It emits no odors or harmful fumes and will not harm humans, pets or irritate the skin. Biodegradable: Contains no acids, caustics, chloride, or volatile organic compounds. Tablet is biodegradable, safe for environment, and completely safe to store and use in the home when used according to directions. Maintenance and Usage: Drop 1 tablet in toilet tank every two weeks to keep toilet systems clean and maintain bacterial balance in the septic tank or cesspool. Older, overtaxed, or neglected systems may require a shock dosage to create a cleaner system and high bacteria level. Qty 12 of CCLS 2-n-1 Blue Toilet Bowl Tablets, Tank Cleaner and Septic/Cess Pool Treatment all-in-one, (6 Month Supply). Chemical Free: Formulated from naturally occurring organisms. Non-toxic, non-hazardous, non-corrosive, non-combustible. It emits no odors or harmful fumes and will not harm humans, pets or irritate the skin. Contains no acids, caustics, chloride, or volatile organic compounds. Tablet is biodegradable, safe for environment, and completely safe to store and use in the home when used according to directions.