SmartSeal Patio Cleaner Xtreme - 5L - Powerful Black Spot Remover Patio Cleaner & Rapid Mould Lichen and Algae Remover for Cleaning Stone Paving, Concrete, Sandstone, Porcelain, Slate & Granite

I seldom leave reviews but felt compelled to write this one. I had a new garden path laid three years ago, at some considerable cost. It is a pale Indian sandstone. We started developing immediate black spot problems and three years later, you could not see some of the stones for the black, they were completely covered. Power washing didn't touch it, and the path looked terrible, with a cloudy finish and masses of black spot all over it. This morning I received this product, put the protective gear on, and thought I will spray neat on the really bad bits and then do a 1:1 dilution and do the rest, as I was worried I wouldn't have enough. As I started to spray the neat product, I did about five stones, and then turned back, and good god, genuinely, the black spot had gone, literally gone. I've now done the rest of the path, with a mix of neat and diluted, and it's like new. This is one of the few products I've ever bought which actually does exactly what it says it does. I will be buying more and using it when required if it comes back. If your patio or path has black spot, honestly don't hesitate, this stuff is brilliant. Totally and utterly worth it. Update, bought again this year, due to the mild winter I had really bad black spot again, I power wash first and use this simply for thr black spot. Put it on in a 50/50 dilution, and the black spots just disappeared , bringing it up like new. It’s like a magic eraser. Brilliant product.

Have ordered this stuff twice recently and can say it has saved my patio and front path. Alot better than expected. Used it a few times on front path with a pressure washer set on highest pressure setting and has Brought it back to nearly new. Anyone who buys this your path/patio may new cleaning a few times but be persistent and this does the job. Will be ordering for 3rd time very soon to do my path in the garden. Saved ££££'s in replacing old path and patio. Highly recommend 👍

Works well. Expensive and I needed more than I thought I would, but it definitely worked well.

The pictures speak for themselves - the horrible grey black streaks in the Indian stone were still there AFTER power-washing. I applied the product almost neat with a spray and it started working immediately. I left it a couple of hours and am thrilled to have the beautiful colours in the paths and patio back again. Regarding the application - easy peasy with a spray, I gave it a light brushing but don’t think that was essential, no ruined clothes and the bleach smell ISN’T that strong. Could probably have diluted it as I didn’t have enough to finish the job but I made the choice to save on effort! I bought direct from Smart Seal and had problems with the delivery. Within three hours of leaving feedback, the seller contacted me, apologised profusely and refunded 30% of the cost - even though there is no delivery charge and I said there was no need. Delighted with the company and the product. It’s up there with the Vileda 1-2 Spray mop which is a life-changer!!

Great patio cleaner.

Really pleased with this product. Have used numerous other patio cleaners before and they haven’t really touched it. I dampened the surface as as per instructions. Applied the liquid 50-50 with a sprinkling water can. Because my slabs are bevelled , the dirt sits in between the ridges so I Scrubbed over each slab with a wire brush. ( purchased on Amazon - see review.) as soon as I applied it… I then left it for 1 1/2 - two hours and then rinsed off with a hose pipe with the spray attachment. Unfortunately, I don’t have a before and after But I attended a during and after.. Delighted with the results. The only thing it did not remove , was a few black spots, but I was expecting that. If it helps how much to use - I purchased 4 containers and used one and a half for the area that you see.

Was fairly dubious as with most claims however, I found this stuff to actually do the job and cut through some of the most stubborn stains on my Indian Stone Paving. I sprayed it on with a garden sprayer, left for an hour then jet washed. Some of the stains were still there so a re-treated those areas whilst concentrating on other sections, its a fairly large patio. When I came back to look at them it had dissolved the black marks and staining. Patio looks extremely good. One word of warning is that this stuff contains bleach so I have ruined a pair of Jogging bottoms with spray back. Unless you like the pink streak look :) Use plenty of water if your near plants or the lawn but after a week I have had no bad reactions and the patio looks great. Only took a star away as it is expensive, I used all of it. And yes I would buy this again

Thought I would try this and was very impressed with the results! Much less effort and mess than pressure washing. Left on for just over an hour. It is expensive but well worth it, would definitely use again and recommend to others.