"INSTANT POWER" MAIN LINE CLEANER Instant Power Main Line Cleaner uses a nonacid formula intended to clear main sewer lines and interior lateral and vertical lines of all obstructions with 1 application. 1 gallon container is intended to be used in 1 application. Best if used in the evening and allowed to work overnight before flushing with hot water in the morning. Highlights: 128 oz. Opens Main Sewer & Lateral Lines Non-Acid Formulation Strong enough to clear main sewer lines from organic obstructions Safe for all pipes and septic systems