SmartSeal Patio Cleaner Xtreme - Powerful Easy To Apply Patio Cleaner Fluid - Highly Concentrated Patio Black Spot Remover and Paving Slab Cleaner - Eradicate Stubborn Patio Black Spots (2 x 5 Litre)

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.

I was doubtful anything like this would work but Jesus Christ, my patio looks better than it did new, I was amazed by it, I’ll definitely be using it again!

Had a patio with 6 years grime and algae. Two applications did the job. A bit pricy which was made worse because I did not have the equipment to use as sparsely as recommended. Never-the-less easy to use. Will use again in 6 years time

Great product so much better than Patio Magic which did not remove the black spots.

Would highly recommend this product. Cleaned patio effortlessly. I shall be ordering this every year. Patio looks brand new!

Very good product. It did what it promised. Took off really ingrained algae and other grime that the Karcher alone couldn't touch. Brought the paving slabs back to a pristine condition.

We had black spot on our Patio and the Liquid was fantastic. It didn’t get rid of it completely but it improved a lot. Would recommend.

Cleans well if you apply it neat or with a small amount of water. For my average sized driveway I would need many of these containers to clean it fully so it's not value for money. I have managed to clean only half, would now be going for a cheaper option at a third of the price, which does about the same and hasn't got such a strong smell.