The Seachem MetroPlex and Seachem Focus are a great one-two punch for treating bacterial diseases, infections and parasites inside and out. You can use both separately, or both at the same time to treat both external and internal issues.
Seachem MetroPlex is an effective and safe treatment for several protozoan and anaerobic bacterial diseases of fish (Cryptocaryon, Hexamita, Ichthyophthirius). The main ingredient is Metronidazole, a medication used to treat infections caused by bacteria or parasites in humans and animals.
Seachem MetroPlex does not impact the biological filter bed and is easily removed with using activated carbon. Seachem notes there is little danger of overdosing, but recommend a dose of 125 mg per 10 gallons of aquarium water.
Seachem Focus is used to treat internal infections. It may be used alone or mixed with other medications to make them palatable to fish when your fish eats the food, will get a more direct and concentrated dose of medications. Overall this increasing the effectiveness of the medicine since you’re not loading up the tank and delivering the medication through the water.
You can combine both together with dry food and water or another liquid food supplement. Just mix it all together, let is sit to absorb into the food for 10-15 minutes and then slowly feed to your fish, trying to target feed to ensure all your fish are getting a proper dose.
Each 5g package runs around $7. At this price, its nice to have some on hand just in case something happens to your tank. Also consider using during quarantine and when adding new fish to an existing system as a preventative measure.