Patio Magic! 16491 Concentrate is a powerful, biodegradable liquid formula designed to eliminate mould, algae, and lichen on patios, paths, fencing, and driveways. Easy to apply and fast-acting, it begins working within days and provides results that last for months. One 2.5L bottle treats up to 85 square metres. Fast-Acting Formula: Starts killing green mould and algae within 2–4 days, visibly improving surface appearance over time. Biodegradable and Long-Lasting: Eco-conscious formula that not only cleans but keeps surfaces protected for months after treatment. Indoor and Outdoor Use: Ideal for patios, driveways, fences, walls, and other hard surfaces – suitable for indoor and outdoor cleaning. Generous Coverage: One 2.5-litre bottle treats up to 85m², making it highly .