Safe and easy to use. Slow release formula designed to Kill lichen, moss and algae over time and works with the weatherto erode growth away. Can be used on a variety of outdoor surfaces including wood decks, painted surfaces, concrete walks and driveways, masonry, plastic furniture, etc. No pressure washing or rinsing required. Spray and walk away, For residential, commercial, industrial, community and government maintenance. Bleach and phosphate free formula with a neutralpH. Mix ratio 1:5, makes 6 gallons. Cleans up to 750-2250 sq. ft. per gallon, depending on thickness of growth and porosity of the surface to be cleaned.