Fish Amoxicillin by Fish Aid Antibiotics, exerts bactericidal action on gram positive and some gram negative bacteria. Fish medicine like Amoxicillin is a broad spectrum antibiotic that is used to halt the multiplication of bacteria. Useful for control of some common bacterial fish diseases including Dropsy, Fin Rot, Red Pest, Aeromonas and Pseudomonas genera and Mycobacterial Group (gill diseases, Chondrococcus)