Concentrated septic system treatment dissolving pacs contain specially blended enzyme-producing bacteria that help digest household waste, reducing sludge buildup in septic tanks and drain fields. Drop this easy-to-use treatment pac in the toilet and flush. Helps prevent backups and controls odors. Treats septic tanks up to 1500 gallons. Safe for all pipes and septic systems. Works with anaerobic and aerobic systems. Three month supply - use one 2 Oz. pac per month.