Instant Fresh Toilet Treatment is a simple one-step, highly effective way to deal with the boat's holding tank that eliminates the need for multiple chemicals. This efficient, biodegradable formula quickly breaks down waste to remove potential odors, while leaving a light, pleasant scent behind. Additionally, special lubricants prevent drain valves from sticking. Also works in portable marine toilets. Features Non-formaldehyde, non-staining, biodegradable formula. Latest technological lubricants keep drain valves from sticking. Breaks down waste quickly and efficiently. One ounce treats five gallons. Fresh pine scent controls holding tank odors Fresh lemon scent controls holding tank odors Complies with EU criteria for biodegradable products; Contains lubricants that prevent drain valves from sticking 16oz/473ml: Treats up to 606 liters 32oz/946ml Treats up to 1211 liters 1 Gallon/3.79L Treats up to 4844 liters Directions Holding Tank Systems: BLACK WATER: Add 30 ml for each 19 liters of tank capacity. Pour through toilet into holding tank and add 4 liters of water. Hot weather and long retention times may require additional treatment. GREY WATER: Use 30 ml for each 38 liters of tank capacity. Pour through shower or sink drain and add 4 liters of water. RECIRCULATION TOILETS: Pour 236 ml into initial water charge. PORTABLE TOILETS: Pour 118 ml into waste holding tank and add water to cover tank bottom.