Patio Black Spot Remover - for All Stone Type - Restore Natural Colour - Removes Stains Caused by Black Spots, Removes Stains Caused by Algae - Biodegradable & Acid-Free - 4 L

I have a 5 acre estate customer, exspencive terra cotta colored sandstone paver patio. Had black lichen everywhere. After reading mixed reviews, I tried it. The secret, follow the instructions. Pay attention to your weather forecast. If you have rain within 48hrs, don't use it. It won't work. I used a spray bottles made for harsh chemicals. One generous pass in sunshine usually enough. I didn't rinse after 2hrs. Didn't have any issues.

I had a bluestone cap on a pillar that was completely black. I used this and it got it all looking like bluestone again with no more black. However, I think the stuff that costs 1/5 as much that is available in hardware stores and big box stores would have done just as good a job. This definitely works but it's very pricey. I would have given it 5 stars if it weren't for the price.

This product is a hoax. Nowhere on Amazon, nor on the product packaging, are the ingredients stated. The results are nothing like what is represented in their video. This product is essentially exorbitantly overpriced bleach. I accidentally got some on my black pants, which now have spots and are ruined - as it splashed with bleach. Don't be duped! This was a very expensive mistake - and of course, it's not returnable.

I tried many products which promised to remove the overwhelming number of unattractive black lichen polka dots in my expensive bluestone pavers. THIS IS THE ONLY PRODUCT THAT WAS ACTUALLY ABLE TO REMOVE THEM! Watch the video and follow the instructions (no scrubbing necessary) ... you will have the experience described. This won Product of the Year at the Chelsea Flower Show ... no higher recommendation ... and is only recently available in the US. Order from the company or from Amazon ... same price. I am ecstatic to have found it!

Worked as advertised

Too many applications needed Changes color from white to yellow color

It certainly works as advertised. It cleaned up the stains/mold on the stone work on the front of my house. A couple of places I had to work over twice but it worked. So note though, this a bleach based product so wear old clothes etc when using it.

seemed like it was just clorolox.

I live in Ontario and my pool pavers have been taken over by lichen. Its been a problem I've trying to solve for years using all sorts of chemicals. I was skeptical by some of the reviews (and because of the cost). But WOW. It works really well.. After 2-3 minutes you will see the lichen turn from black to brown and then dissolve. It's super satisfying. It also removed algae and tannins (dead leaf stains). Couple of notes. Follow the video instructions. Saturate the stones with the product..not while under the sun or while they are hot.