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)

Excellent. I had to do two coats but my stones were terrible. My garden looks fab now. It removed all the stains it's supposed to. It didn't remove a few stains I have from other spillages but that's as expected.I did two coats over a few days. I tried a third coat but it looked like the 3rd coat might be causing discolouration.I would 100% recommend this product for embedded black stains on paving stones.

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.

It was good, you will have to buy more than one to actually work. Used alot of water to get the spots off.

This product removed the black spots from the paviors on my driveway and also cleaned my pathway slabs in a way that pressure washing alone never could. I recently re-ordered another container to complete the remainder of the driveway.

I've tried a few other "miracle" workers over the last couple of weeks, so the first picture is after I've already used several things, so originally the lichen was even worse! (Moved in to a house with a patio that likely hasn't been looked after in 17 years).I wasn't expecting too much from this, in fact I was pretty much ready to admit defeat but this was my last attempt at getting rid of the lichen or fading it some more.Well, wow, just wow! The directions say to leave it for at least 2 hours, I've left it for about one because my animals were getting impatient, so needed to wash it off and let it dry, so just about an hour and the lichen just disappeared, it started working really quickly, like surprisingly quickly, within minutes I saw it fading in places. There are still places which I clearly didn't cover properly so will need a second go and some of the more stubborn lichen has faded considerably but not fully, but I was not expecting results THIS amazing.If you've just discovered lichen and it immediately became your arch enemy, look no further, this stuff will help you get rid of it at last!Hoping to never see lichen again, but if I do - I'll be back for more!

Why did you choose this product over others?:The advert and what it promised.Unfortunately it did not live up to the advertised performance, after two soaks and two power washes there are still black spots

Why did you choose this product over others?:I chose this product after doing a lot of research and reading a lot of reviews.I have Indian stone covered yrly with black spot and this is the only product that removes it.It's very easy to use and is very strong.I used a spray for overall coverage and then tipped it straight on to tougher areas. I live in an old forest so black spot is a yrly issue and this is the only product that has worked.

My Indian Sandstone patio had many black algae spots that have developed oner a 20 year period and 800psi jet washing has not removed them. I decided to try a chemical treatment and after googling a ranking of competitive products decided on Ultimate Black Spot which was ranked a marginal third position but was significantly cheaper that the other products that were ranked. I waited for a rare dry day and applied the solution using a a garden pressure spray. Left it to soak for 4 hours then hosed the patio off. Pro Kleen removed almost all of the black spots the patio looks really clean and bright. We have a big patio and the 5 litres of Pro Kleen was not enough the complete the job. I downloaded the MSDS for Pro Kleen Black Spot Remover to ascertain if there were any additional components to the 9.8% sodium hypochlorite (bleach) which would help penetration and treatment but no other chemicals were listed. Rather than spend £28 for another bottle of Pro Kleen and wait several days for delivery and dry weather I decided to try basic commercial 10% thin bleach (NaOCl) on the remaining area. This appeared to work as well as the ProKleen area for £2.50 for 2 litres commercial bleach (not the thickened 5% bleach from Tesco which also contains surfactants). Next job is seal the patio stone to hopefully retard ,or stop, algae re-growth). I would have given 5 stars if I had not tried and compared commercial bleach treatment for a fifth of the price.