HG algae and mould remover is an effective algae and remover. Overtime, algae and mould can build up on patios, walls, roofs, and all types of concrete outdoors. When you apply this algae killer, it penetrates deep into the surface of the concrete.  As well as removing algae and mould, it also protects your patio against algae building up again for months. Another key benefit of HG algae and mould remover is that it isn’t harmful to your grass or plants, so you can keep your patio and garden looking great.This effective algae cleaner makes your patio cleaner and your life easier.