Metroplex is a safe and effective treatment for several anaerobic bacterial and protozoal diseases of fish (Cryptocarion, Hexamita, Ichthyophthirius). No adverse effects on the bed of filtration and is easily removed with carbon. There is a small risk of over dosage. The usual dose is 125 mg every 40 gallons of water. For use in freshwater aquariums or marine. Metroplex treat parasitic and bacterial infections.