GardenersDream Patio Cleaner 1 x 5L - Ready To Use Outdoor Algae & Mould Remover for Fencing Decking Patios Outside Ready 5 Litre Bottle of Pet Safe Just Simply Spray Solution :
Patio Magic! 16491 Concentrate: Ideal for Patios, Paths and Driveways (Kills Algae and Lichens), 2.5 Litres : Amazon.co.uk: Garden