30 SECONDS, 64 OZ, Spray & Walk Away Surface Cleaner With Hose End Sprayer, Kills Lichen, Moss & Algae, No Pressure Washing, Rinsing, Scrubbing, Or Hosing Required, Simply Spray & Walk Away, Results Become Visible Over Time Works On Many Outdoor Surfaces Like Roofs, Sealed Concrete, Asphalt Driveways & More Bleach & Phosphate Free, With A Neutral Ph, Improves Traction On Many Surfaces, As Well As Appearance.