Wet & Forget Moss, Mold, Mildew, & Algae Stain Remover Multi-Surface Outdoor Cleaner Concentrate, Original, 128 Fluid Ounces

Waste of money and time, not beneficial at all.

This WnF is soooo great. A friend told me that the darkening of concrete over time is usually tiny black mold. WnF attacks that and brings your concrete bright again! Take before photos, apply, and then be patient. In 2-4 weeks you will see the result is bright white sidewalks and driveway, and very long-lasting. I regret pressure-washing my former driveway, as it removed small amounts of the surface; accelerating the concrete aging. However, WnF is not only easier, it lasts far longer than pressure-washing without removing parts of the surface. Because you need to wait weeks to see the result it is not as gratifying when applying. But know that it works; take before and after photos —or— test on one “square” of your sidewalk first. After a few weeks, that will be brighter than the adjacent squares. If you have green active growth on your stonework or shaded areas. You may notice it turn orange as the enzymes begin working. Any thick growth may later require removal, but WnF increases the length of time before growth returns. Usually several years in my experience. I use it on my concrete driveway, sidewalks, brick + mortar, and even the shaded side of my kids’ wooden playset roof. I used it on the padded portions of my boat trailer to make it look brand new, also. I am not an expert on what surfaces to avoid, but I avoid plants + grass and I allow to dry before my pets walk on it. Definitely purchase the concentrate and determine your own dilution. When I have tried the gardenhose-end variant of this WnF product, it appears less-effective. Always apply early morning or late evening so it can maximize before the sun evaporates. Also apply when you don’t think it will rain for 24 hours (turn off your sprinkler system for a day, if you have one). I hope that helps! I cannot say enough about how great this stuff works!

This stuff works! I love it! The mildew is gone after a few days!

This product is amazing. I am a 72 y/o woman who lives in the Pacific Northwest where we have damp weather from fall through spring. My walkway to the house becomes hazardous with algae, mildew and mold. I sprayed the area, and within a day, the results were impressive. Far less strenuous than pressure washing. Just keep pets off the area for 4 hours allowing it to dry completely.

This cleaner does a decent job on newer outdoor stains — it lightens moss and mildew without harsh scrubbing, and I like that it’s gentle on surfaces. It’s easy to mix and apply, and the coverage goes a long way for decks, siding, or concrete. However, for older or deeply set stains, it’s not a miracle fix. You’ll likely need a scrub brush or some extra effort to get those areas truly clean. After using it a few times, I’d say it’s effective for maintenance and prevention, but not strong enough to replace a good scrub for long-standing buildup. A practical cleaner for regular upkeep — just don’t expect it to erase years of outdoor grime on its own. 🌧️🧽 — #1 Maryland Homeschool Oversight Program

It’s easy to use and make more solution. It does work but it requires patience. It does get the moss.