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

If you are tired of the aggressive roar and back-breaking labor of a pressure washer, Wet & Forget is often cited as the "lazy person’s dream" for home maintenance. However, the name is a bit of a double-edged sword: you truly can "forget" the manual labor, but you also have to "forget" about seeing results for a few weeks (or months). How It Works: The "Slow Burn" Strategy Unlike bleach-based cleaners that whiten surfaces instantly through a chemical reaction, Wet & Forget uses a non-caustic, pH-neutral formula (primarily alkyl dimethyl benzyl ammonium chloride). • The Process: You spray the solution on a dry surface. It kills the organic growth (moss, mold, algae) at the root. • The "Worker": Once the organisms are dead, the weather takes over. Rain and wind gently wash away the dead debris over time. The Pros • Zero Scrubbing: This is the biggest selling point. You spray it on and walk away. No rinsing is required. • Surface Safe: Because it contains no bleach or ammonia, it won’t damage your siding, roof shingles, or deck finish. It’s also much safer for surrounding landscaping than harsh caustic cleaners. • Long-Lasting: Once a surface is clean, the residual effect of the product helps prevent regrowth for up to 12–18 months. • Reach: The "Xtreme Reach" hose-end version can spray up to 30 feet, allowing you to treat second-story siding or roofs without ever touching a ladder. The Cons • The Waiting Game: This is not for people prepping for a backyard party tomorrow. Green algae usually disappears in 1–2 weeks, but black mold or thick moss can take 3–6 months to fully clear. • Weather Dependent: You need a dry day for application (at least 4–5 hours of dry time), but then you need subsequent rain to actually wash the stains away. If you live in a drought-prone area, you might have to manually hose it down once a week to see progress. • Not for "Dirt": It only works on organic growth. It will not remove mud, clay, or grease stains. Wet & Forget is an elite product if you are a proactive maintenance-taker. If you apply it every spring as a preventative measure, your house will stay pristine year-round without you ever breaking a sweat. Pro Tip: If your concrete is currently "black" with years of buildup, hit it with a pressure washer once to get a clean slate, then apply Wet & Forget every year after to ensure you never have to pressure wash again.

I have several stone patios, stairs, and walkways. We have a lot of trees around our property and the stonework gets its share of mold and mildew. I used to buy a very expensive mildew remover that worked with a pressure washer. For the first few years, that worked fine but took a long time to do. Over time, some mold and mildew got into the stonework deep enough that pressure washer just wasn't enough. Someone told me about Wet & Forget so I gave it a try last fall. Boy did it work great!! Now it doesn't work immediately. It does take a few to several weeks to work. But my stonework looks like it was brand new. It is very easy to use. You mix the proper ratio of it with water in a hand sprayer and simply spray it on. It goes much faster than a pressure washer. I think the label says reapply after a few months but I think I'll only need to do two applications per year. This is a great product in my opinion and I recommend it.

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!

I was doing so well with the wet part of the procedure, but then, as the product clearly stated, I forgot the rest. And so my review is brief but factual. It starts out wet, and then....

This stuff really works. I used on both algae and moss. Both required two treatments but the results were excellent. Two months later, I see a small intrusion of the stubborn algae, but the moss in other locations was eradicated. I used it on a portion of my tile roof several years ago, and that part is clear and clean while the remainder has got algae and moss growth. Lesson: do the whole roof next time. Highly recommended and is rinse free.

I have been using Wet and Forget for years to keep my concrete driveways and sidewalks from turning black (or get them back in shape if already black). Appying this stuff is far easier than pressure washing (just spray it on) and does not damage the surface as pressure washing often does (chews off the smooth surface, exposing the agregate). The only downside is it takes a long time to see results. Months usually. But it DOES work. And once you get those surfaces back in shape, it is easier to keep them clean. Just reapply Wet and Forget every couple of years (or sooner if necessary) to keep the remove any returning mold and mildew.

This product is know that it works. But I was looking for something quicker to destroy the algie. It did kill the algie turned it gray. I still had to scrub the walls by pressure washing.

My husband and I have been using this for a year now — seven times and counting. The before and after speaks for itself. Our cement patio went from dingy and stained to looking completely brand new every single time. The stain removal is seriously impressive and it always dries streak-free. Fast results with zero scrubbing, which we love. The scent is mild and not overwhelming at all. And the value for money? Unbeatable — one jug goes a long way. This is a permanent staple in our home now. If your outdoor surfaces need help, just get it. You won’t regret it!

Waste of money and time, not beneficial at all.