Esha Optima fish health booster is a unique combination of trace elements, minerals and vitamins that are absent from tap and reverse osmosis water. These ingredients help recreate a natural environment for your fish. Esha Optima fish health booster Boosts fish health Increases resistance to disease Helps induce spawning.  Esha Optima fish health booster helps sick or injured fish recover quickly, it also increases resistance to parasites. A water change followed by a dose of Esha Optima will help induce spawning.  Standard dose 20 drops per 100 litres (22 gallons) 20ml treats 2000 litres (440 gallons)