Oatey 35315, 1 Gallon 128 OZ, Hercules, Fuel Oil Sludge Treat, Storage Tank Additive, Cleans & Conditions, Helps Prevent Fuel Related Heating System Failure, Improves Combustion Efficiency, Reduces Soot Formation, Prevents Fuel Oil Waxing & Gelling, Disperses Condensate Water, Helps Avoid Water Blocked Filters While Cleaning Strainers, Nozzles, Pumps & Burners & Minimizing Burner Breakdown, Prevents Sludge Build Up & Ice Formation, QT Treats Approximately 500 Gallons. The Oatey 128 oz. Fuel Oil Sludge Treatment disperses sludge and emulsifies water in oil tanks to help eliminate burner breakdown, sludge formation and winter freezing. Discourages soot formation and helps conserve energy. Helps avoid breakdowns from clogged lines, strainers and nozzles.