Non-harmful to fish and aquatic plants when used as directed. Alternative to harsh chemicals – Chlorine, copper and phosphate-free. Begins working on contact, killing algae fast; results in 24 to 48 hours. Immediately begins fighting algae blooms, releasing vital oxygen into the water body as it biodegrades. Calculate the volume of water in the pond correctly. Lenght (m) X width (m) X depth (m) x 1000 =volume in litres Mix powder in a bucket with some pond water and spread evenly around the pond. Make sure the pond is well aerated.