Waterlife Octozin is a treatment for internal parasites such as those which cause Sleeping Sickness Hole - In - The - Head Seawater Angelfish and Clownfish Disease Malawi Bloat Disease and also early stages of Dropsy. Octozin may also be used to treat Whitespot in seawater aquaria where Cuprazin cannot be used. It is harmless to invertebrates and algae when used as directed. You will require three separate days of treatment to complete the course. Octozin is active for up to 3 days after the last day of use. Although internal parasites are destroyed instantly external signs of improvement to the fish may take up to 7 days. Always read instructions fully before use. Suitable for seawater tropical freshwater and coldwater aquaria. 21 tablet (3 day course for 159 litres). Also available in 80 Tablet (3 day course for 600 litres).