Pro-KleenUltimate 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)

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.

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.

Great product worked well , worth the purchase…

Worked really well but wear old clothing! It will splash and bleach!

Brilliant stuff. Does what it says! Shake it well & spray on patio, 'hey presto', black spots, algae, gone like magic!!You can see it working it's magic straight away. Most spots gone by 5hours butI left for 24hours.

Brilliant my Indian stone patio looks brand new. Jet washed patio first to remove dirt then let it dry. Poured the black spot liquid into a hand bottle sprayer and treated whole area. After a few minutes it was already working. Left for an hour then jet washed again. Patio is pristine no black spot left.

I made the mistake of thinking that I would need to dilute it and it would be enough for my patio, Nope... it is to be used "as is" and was barely enough.Yes , it did the job but it was not that much better than other similar brands. It was far too expensive for me to consider using again.

I was sceptical, but I am very impressed. I have a large patio and one container was enough (with some left over). So easy to use (I painted it onto the tiles with a large brush). Left the product on for about 6 hours then pressure washed off. Very pleased with the result.