This innovative cleaner uses advanced nano technology to remove most kinds of algae and moss from stone brick and concrete surfaces without the back breaking work of scrubbing simply spray or brush on the liquid formula and leave it to work in just 2 3 days years of built up dirt and grime disappears leaving a beautifully restored finish and an invisible barrier to inhibit re growthworks on stone brickwork masonry and wooden deckssingle 500ml bottle treats approx 100sq metres 1000sq f