Pro-Kleen Ultimate Black Spot Remover and Destroyer for Patio, Stone, Block Paving, Indian Sandstone, and more. Easy to Use Fluid that Powers Through Stubborn Dirt & Grime (5 Litres)

Works brilliantly. In the photos, the 'dirty' slabs on my patio have already been power washed to remove dirt and grime, and left behind were the black spots and other algae. I already thought the difference between uncleaned slabs and power washed slabs was significant (yes, they were pretty filthy). What a difference this stuff made!!Used 3 full tubs (15 litres) of it for approx. 50 sq. m. of patio slabs. Could possibly have put it on a bit thinner to make it go further, but first time using it on 5 or so years of build up, so was ok with possibly putting to much on.Left it for approx. 3 hours, although you could see it working after a few minutes, then power washed the slabs clean again to remove any residue, and POW! The slabs look like new! Cleaned up better than I thought and brought the colour back out again!A couple of very heavily affected areas, or areas I maybe put it on too thinly, still have a few visible black spots, but over the whole patio, very little was left. Awesome stuff!!

Does exactly what is says. I jet washed my Indian Sand Stone patio first to get rid of the dirt and green after winter. I didn’t go to mad because I’d already tested the black spot remover beforehand. I used a spray bottle to apply the following day once the patio had dried. Then left it for 3hours, the black spots were gone. I have a few large areas of rust where I’ve had metal pots standing and unfortunately these stains were still there. I’m still looking for a product that removes rust the. My patio would look like it had just been laid otherwise, it’s actually been down for about 15 years! I am so impressed with how this has worked with minimal effort and Will definitely be using it again as and when needed.

Managed to remove most of the black spots on my paving slabs that my pressure washer alone couldn't get rid of. I did have to apply a second coat as it was a warm day which meant the solution had started to dry out within about 2 hours in places. I think another application would get rid of the last few spots but I'm happy enough with the results for now. My only real criticism is that it's expensive for what you get when you can buy "unbranded" sodium hypochlorite at about the same strength (or higher) for much cheaper.

What a fantastic product! I painted it on as I found this easier than spraying it on the sandstone slabs (do the whole paving slab or it looks very patchy). Within hours the slabs looked almost like new! Depending on the type of stone, some came clean much quicker than others, although a few needed more than one coat as they had a lot of dense black algae spots so it was left it on for several hours. It's like a strong bleach and it removed all the dirty build up which didn't come off with pressure washing. The patio now looks like new - truly amazing. The best £30 I've spent in ages.

Delivered quickly with just the correct amount of packaging. Think it came a day early - very competitive pricing.Have white porcelain slabs in back garden which have been down for eight years. After pressure washing there were lots of black marks which we can normally clean with bleach. Unfortunately this year our normal cleaning methods didn’t work. Our next door neighbour recommended this product. Checked online that it was suitable and tested it before it was used on the whole area. Couldn’t believe the transformation! It says to leave for 2-4 hours before you wash it off but ours was clean in about 30 mins. It was recommended to wash off using a pressure washer but I only used the hose. Our patio is in the shade so the pictures don’t really what a difference this product has made. A fantastic product. Highly recommend.

I’m so impressed with this product it has transformed my patio that my husband layed 5 years ago. But didn’t seal the patio so I’ve used the black spot remover & 5 hrs later I washed off the product. I will need to use the black spot remover on one very stubborn slab then the patio will be ready to seal. Brilliant product & considering the size of the patio I’ve got loads left over which I’m going to use on my mums patio. 10/10

Sprayed area as instructed, left for 3 hours and jet wished off. Yes it did clean very well and get rid of a lot of the black spots but still left quite a bit so not as strong as it says it is. Perhaps another going over would help but at £30 is is very over priced.Added some photos of the black spot it left.In summary is is ok, not great though and I would not recommend it at that price. if you can find strong bleach and water it will do the same job for black spot anyway.

Works perfectly and easy to use