Tetra general tonic plus 20ml is a multi-purpose remedy designed to treat the common freshwater fish diseases. It helps with bacterial infections and ectoparasitic diseases too. 1.5Ml will treat 100l of aquarium water for 1 day. Please ensure the instructions provided with the product are used to ensure the safe usage of this product.. Features. Multi-purpose remedy. Helps treat common diseases. 1.5Ml treats 100l of aquarium water a day. Easy to use