Removes stubborn dirt, pollen, mildew, algae, fungus, and other organism that cause unsightly roof stains. Our container holds 40 lbs. or 4 gallons of concentrate. When mixed properly 10:1 (i.e. 10 gallons of water with 1 gallon on Roof Cleaner MX) and applied with garden sprayer or applicator. See instructions for further detail.