Wet & Forget Outdoor Moss, Mold, Mildew, & Algae Stain Remover Multi-Surface Cleaner, Ready to Use, 64 Ounce

This product is great. I had a new cement poured and a month later l put a flower planter on it. The planter leaked water on it and left a large stain on my new cement l tried to remove it using bleach, ammonia, even a power washer. Nothing worked so l went online and found your product. I had been using a wire brush to help scrub the cement. I applied a coat of your product let it sit for about 5 minutes. 75 percent came off. I repeated the process and it removed the remaining stain. I was so happy that my new cement !looked new at Great product, l highly recommend it!!

Wonderful at removing lichens and moss! The sprayer doesn't work so nicely on those sold with sprayers, so I pour into empty cleaner spray bottles and it goes on much easier.

The sprayer was bad! I followed directions and no matter how many times I pushed the spray handle it wouldn't push through any solution. Finally ended up putting the solution into a different sprayer.

This product works well on everything I have tried it on - brick, concrete and canvas. For a brick patio, a concrete retaining wall, and some canvas awnings, I tried a lot of products without success. Wet and Forget, however, did the job. BUT, it requires patience. A lot of the one star reviews talk about how nothing changed in a few weeks or a few months, and this is correct. If you want fast results, put a lot of work into scrubbing and scrapping and/or bleaching as is appropriate. If you don't want to do that much work, do as the label says - wet the surface and then forget about it for quite a while.Let me give you an couple of examples. I had a lot of moss and green stains on a concrete retaining wall. Last spring, I sprayed the moss and stains with Wet and Forget. Nothing really happened that summer; I guessed that it just didn't work that well. This spring, however, all the moss was dead and all the green stains were gone. Same results with black mildew stains on a canvas awning. Sprayed last year; nothing much happened. This spring, all the stains were gone. I believe the product literature says it may take up to a year for some stains to disappear.I also had a very bad moss problem with a brick patio. First, I stopped trying to clean the bricks with a pressure sprayer. All that did was make the brick wet through and through (brick is porous), which made the problem worse. I used Wet and Forget, and that solved the problem. Granted, it took a while and more than one application over a couple of years, but nothing else I tried even made a dent in the problem.So, be patient. It does work.

Pro: I purchased 3 of these to cover the area that needed to be cleaned of mold, spattered black spots of unknown origin, and green algae on concrete. The trigger was easy to use, no smell, no leakage, big size, and has a trigger spray or stream that my hands were able to use for two hours which was a pleasant surprise because I have arthritis in my fingers and joints. I only used the stream instead of the spray nozzle because it dispensed a larger quantity onto the concrete. The container is attractive, but I found it too heavy to carry for long, even switching hands frequently. I'm shorter in height so I could set it down on the ground sometimes and that helped me finish the job.Con: I didn't see any changes in the appearance of the concrete, but the bottle states it can take anywhere from a month to a year for it to work it's magic. Obviously, there is no way to currently review its' effectiveness at this point! I've given it a 3 star rating for now, but if Amazon lets me, I'll come back to comment on any changes when I see any.UPDATE: 3 MONTHS LATER - Well, it's definitely doing something, but not enough to change it up from 3 stars. All of the green algae is gone, but the black spots are mostly a medium gray color now. None of the sidewalks are actually clean without discoloration though so at this point I doubt I'll purchase any more of them. If it changes in the future to an even concrete color I'll be back to update it. No updates will mean that no further improvement has been noted in another 3 to 6 months.

Waste of money, to be completely honest. Sprayed it on my patio, and after a day and a half, it looked exactly like it had before that. The sprayer is good, the bottle is good, but the spray effectiveness just isn't worth it. I ended up using a foaming cleaner designed for siding/patio/etc. and a pressure washer to clean. Now, my patio has years of mildew on it, and the spray sounded too good to be true, but nothing. Some places where I soaked it on, it turned white from being soaked with spray, but wasn't clean, just alot of spray made it look white. And again, once rinsed after a day and a half, nothing. Maybe your results will be different, but mine was not a positive experience.

I noticed my fence turning green so that’s when I turned to Amazon to find something to clean it. As soon as I saw the Wet & Forget brand, I purchased without hesitation! I swear by their shower cleaner. The horizontal fence posts turned greens so I only did the top two along the fence and skipped the bottom since this spray will give you a hand cramp and I was almost out. I’m glad I skipped the bottom since it gave me an excellent before and after picture! The green is all gone from the top two posts and you can see the difference! In the picture, you can see green on the bottom but not on the top horizontal post. I can’t wait to do the rest since it did such a great job.