Corrosion Technologies 79008 Hammerhead 1 quart bottle Eliminates even powerful odors in seconds More than 5 Billion waste-eating bacteria and enzymes per oz. Great for marine heads, portable toilets, septic tanks, RV and aircraft lavatories 2 oz. will effectively treat a 40-gallon gray or black water tank 1 quart treats a 1,500 gallon septic system