Removes Stubborn Black SpotsThis super-concentrated, Xtreme Patio & Path Cleaner is all you need to eradicate even the most stubborn and unsightly black spots from around your garden - clean your patio, paths, Indian sandstone, block paving, and so much more with ease. It helps to lift and clean dirt and grime from areas that haven't been treated for years - you'll have them looking brand new once more with this powerful black spot destroying solution.Safe To Use On Almost All StoneXtreme Patio & Path Cleaner is suitable for use on almost all treated and untreated stone surfaces. It’s safe for use on block paving, bricks, Indian sandstone, York stone, garden paths, and moreMade To Destroy LichenBlack spots are known as lichen, and they appear when bacteria or algae combine with a fungus. The two organisms then anchor themselves to a surface to create stubborn black spots that are nearly impossible to remove. Black Spot Remover breaks down the source of those stubborn spots - bacteria, algae, and fungus - from hard surfaces, so you can simply rinse them away!Please Note:Avoid contact with grass, plants, and ponds. Contains ingredients dangerous to aquatic life. Children and pets must be excluded from treated areas until the treatment is completed, has been rinsed, and the area has dried.