Maracyn Bacterial Treatsment Powder for Freshwater & Saltwater Aquariums Fritz Maracyn Aquarium Medication by Fritz Aquatics treats and controls a number of pathogenic bacteria that can cause serious disease and even death in aquarium fish. This safe, fast-acting powder formula is non-toxic to invertebrates and safe for use in fresh and marine aquariums. FeaturesProvides relief from bacterial infectionsTreats body fungus, gill disease and popeyeFast dissolving powder medicationSpecificationsWeight: 0.1 lbs