MetroPlex is an effective and safe treatment for several protozoan and anaerobic bacterial diseases of fish (Cryptocaryon, Hexamita, Ichthyophthirius). It does not adversely affect the filter bed and is easily removed with carbon. It can either be dosed into the water or combined in a medicated food mix. It will treat both internal and external infections regardless of the delivery method. When used in a medicated food mix, it is excellent for treating parasites in tanks that contain invertebrates. MetroPlex is gentle and there is little danger of overdosing.