Clears green water fast and helps to maximise oxygen availability for a sparkling clear pond. Targets the tiny unicellular algae in ponds and binds them into biodegradable clumps that sink to the bottom of the pond. These clumps can then be easily removed using a net or pond vacuum. If left they can deplete the oxygen in the water and stimulate new algae growth. Harmless to all pond fish, plants and other wildlife. 250ml treats up to 2,250 litres (500 gallons).