Outdoor ready-to-use is the easy way to eliminate tough moss, mold, mildew and algae stains from your smaller outdoor surfaces. Use on porch steps, fountains, concrete, landscape stones, boat seats, fabric patio umbrellas or virtually any other small outdoor job! Simply spray the contaminated surface and you're done!goes to work with the wind and rain to gently break down the growth and wash it way over the next few weeks or months. There's no scrubbing, no rinsing, and no power washing, the gentle formula contains no bleach or acidic chemicals so it wont harm the surfaces being cleaned, and it is the easiest way to keep your outdoor surfaces clean.