Seachem MetroPlex is a reliable and secure solution for treating various protozoan and anaerobic bacterial infections in fish, such as Cryptocaryon, Hexamita, and Ichthyophthirius. It poses no threat to the filtration system and can be easily cleared using carbon. The risk of overdosing is minimal. The standard dosage is 125 mg per 10 gallons of water. This product contains metronidazole as its active ingredient.