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Wet & Forget

Wet & Forget Outdoor Cleaner & Stain Remover - Mold, Mildew & Algae, 128oz

  • Based on 2,436 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Oct 6
Order within 17 hours and 59 minutes
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Features

  • Wet & Forget Concentrate Outdoor Cleaner removes green and black stains caused by moss, mold, mildew, and algae, no scrubbing, no rinsing, no pressure washing, just wet it and forget
  • Surfaces including driveway, patio, roof, siding, deck, vinyl, wood, concrete, canvas, aluminum, and upholstery
  • Mix 1 part Wet & Forget with 5 parts water in a garden sprayer, spray dry surface on a cool day to avoid rapid evaporation of product, do not rinse, apply when rain is not forecasted within 4-5 hours
  • Apply when the temperature is above 32 F; unused product can be stored mixed and ready in sprayer for future applications
  • Cleans with the wind and rain, green stains clean up within 1-2 weeks, black stains or heavy, stubborn stains can take several months, long-established stains may take 6-12 months; surfaces can stay clean up to 1 year or longer

Description

Wet & Forget is an outdoor cleaner that eliminates black and green stains caused by moss, mold, mildew and algae without any scrubbing, power washing or bleach. Just mix 5 parts water with 1 part Wet & Forget in a pump up garden sprayer. Fully saturate a dry surface with Wet & Forget on a cool dry day and leave it. That’s it! Just wet it and forget it. Wet & Forget goes to work with the wind and rain to gently clean the surface. Green stains generally clean up within a few weeks, a few days with rainfall. Black stains or heavy stubborn stains may take 6-12 months to fully clean up. Be Patient! Wet & Forget properly cleans surfaces, so they are likely to stay clean up to 1 year or longer. Repeat application yearly or when new stains appear to maintain a clean surface. Wet & Forget contains no bleach and is safe to use on any outdoor surface including any type of deck, siding, roof, walkway, patio, brick, and cement. Gallon Concentrate makes 6-Gallons and covers 750 - 2,250 sq. ft. depending upon severity of the stain and porosity of the surface. Wet & Forget - the easy way to clean all your outdoor surfaces

Product Dimensions ‏ : ‎ 5.1 x 7.1 x 10.3 inches; 8.79 pounds


Item model number ‏ : ‎ 800128-A


Date First Available ‏ : ‎ November 18, 2024


Manufacturer ‏ : ‎ Wet & Forget


Best Sellers Rank: #10,440 in Health & Household (See Top 100 in Health & Household) #13 in Household Mold & Mildew Removers


#13 in Household Mold & Mildew Removers:


Customer Reviews: 4.3 4.3 out of 5 stars (2,436)


Item Form: Liquid


Scent: Unscented


Specific Uses For Product: Concrete, Deck, Roof, Siding, Wood


Surface Recommendation: Concrete


Special Features: Multi Purpose


Cleaning Agent Formulation: Stain Remover


Item Volume: 128 fluid ounces


Unit Count: 128 Fluid Ounces


Number of Items: 1


Size: 128 Fl Oz (Pack of 1)


Brand Name: Wet & Forget


Global Trade Identification Number: 33


Manufacturer: Wet & Forget


UPC: 879288000633


Item Highlight: Bleach-free, outdoor cleaner removes green & black stains on decks, patios, fences with wind & rain; no scrubbing or rinsing


Model Number: 800128-A


Part Number: 800128-A


Material Features: Fragrance Free


Material Type Free: Bleach Free


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Oct 6

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Wet & Forget Moss, Mold, Mildew, & Algae Stain Remover Multi-Surface Outdoor Cleaner
Size: 128 Fl Oz (Pack of 1)
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. ... show more
Reviewed in the United States on May 12, 2026 by Fanofsam1
    • Great product a must have
Size: 128 Fl Oz (Pack of 1)
Bad a$$ stuff works great been over a year since application still no mold on house will buy again
Reviewed in the United States on September 26, 2026 by Justin
    • This stuff is magic
Size: 128 Fl Oz (Pack of 1)
I don't know how this stuff works, but I've been using it for years. I just spray it on my siding and vinyl fence once a year and slowly it eats the mold and makes it look brand new again. Not sure why it only lasts a year, but it only takes one day a year to spray the places that get moldy.
Reviewed in the United States on August 23, 2026 by Sam Collins
    • No miracle worker, but a decent product
Size: 128 Fl Oz (Pack of 1)
Happy enough with it. It's not a miracle-worker, but it does reduce algae and mildew. Nothing will beat good old elbow grease, but this stuff is good for spraying hard-to-reach or dangerous areas. It'll probably take multiples sprays/coats to work. In places where the sun doesn't reach, it'll be weaker, as should be expected, though it's tough since shade is also probably where mildew and such will be worst. Pleased enough with the purchase. Be sure you have some way to spray the solution once you've mixed it up, like in a hose or a pump. ... show more
Reviewed in the United States on July 19, 2026 by Phoenix_AZ_1899
    • Worth the wait for lasting results!
Size: 128 Fl Oz (Pack of 1)
Review Image by Jillian
Review Image by Jillian
This definitely works over time so don’t expect immediate results, but the before and afters from my house exterior in a VERY humid climate speak for themselves. Not only did this product get rid of the previous mold build up, it also significantly slowed down new growth. My before and after photos are about 4 months apart and those 4 months were during the most hot, wet, humid time of year. Highly recommend! ... show more
Reviewed in the United States on September 13, 2026 by Jillian
    • Great product, I wish the price would kept at the price I boughted and not going up.
Size: 128 Fl Oz (Pack of 1)
It sure is better to spray this product than using a power pressure Washer machine. I spray this product for months now, and I haven't seen the green Algae Stain or black moss. I live in the tropical where it rains a lot, therefore moss and algae is more propense to reappear, and this product has been a back saver. The only bad thing I have to say about it, is that its price has gone up since last time I bought it, from about $30.00 to $$44.00+. ... show more
Reviewed in the United States on July 11, 2026 by IGB
    • Kills moss, but read the directions and follow them. It will kill fish, plants, and harm humans
Size: 128 Fl Oz (Pack of 1)
I used a garden sprayer to spray the moss on our roof with wet and forget. Yes, it kills the moss. BUT- read the directions and follow them! My sprayer was new and the fitting came loose, leaking on my hand, back and leg. It was 20+ minutes before I washed it off. I was pretty sick for the next week, rash, fatigue, itching, brain fog. Also note the comment about not spraying near water. I was on the roof and doing my best to spray with low pressure but there was a lot of atomization and the breeze carried this everywhere. I was wearing a mask but probably should have had a full body suit and glasses on. This mist made its way to our little 90- gallon pond next to house and killed all the fish. Yes, I learned my lesson, the instructions say not to spray near water; I should have covered the pond; what appeared to be a little mist up on the roof went a long way on the environment. We made it 20 years in the pacific northwest without moss issues but the last few years, something has changed and we are getting consistent moss growth on the roof, rock walls, deck, and all around. My mixed review is based on the fact that it works, but this seems like a harsh chemical for the environment and the user. I don't know if I can recommend this or not My wife is hard set against it as she maintains a healthy garden around the house with many animals and critters. ... show more
Reviewed in the United States on April 7, 2026 by Mark M.
    • Not impressed
Size: 128 Fl Oz (Pack of 1)
Worked well , killed the mold but left the after product on the siding . I had to power wash and brush it off .
Reviewed in the United States on September 28, 2026 by Dwight Mckay

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