Remove unsightly and slippery moss lichens mould and algae from paving concrete and fencing without scrubbing simply spray on the green clean leave and see the results in just 48 hours green clean is wildlife friendly and can be used on stone wood and terracotta children and animals should be kept away for 48 hours after use non hazardous once dry 1 litre covers 8 sq m 25 litres covers 20 sq m and is the refill for the 1 litre click to view green clean instructions