A bacterial infection and a protozoan parasite call for entirely different treatments, and Seachem covers each with a dedicated formula rather than a single broad-spectrum product.
Choosing the Right Treatment
- KanaPlex - a kanamycin-based broad-spectrum antibiotic for bacterial and fungal fish diseases, including dropsy, popeye, fin/tail rot, and septicemia.
- MetroPlex - a metronidazole-based treatment for protozoan parasites like Cryptocaryon, Hexamita, and Ichthyophthirius (ich), along with anaerobic bacteria.
Identifying What You're Treating
- Dropsy, popeye, fin or tail rot, or septicemia symptoms point toward a bacterial cause - KanaPlex targets these directly.
- White spots, cloudy eyes from protozoan activity, or known ich/Cryptocaryon outbreaks call for MetroPlex's antiparasitic action instead.
- When in doubt, isolate and observe symptoms closely before choosing a treatment, since bacterial and parasitic infections need different medications entirely.
How to Use Them
- Treat in quarantine when possible rather than dosing the main display.
- Complete the full treatment course, since stopping early after symptoms improve risks incomplete treatment and resistance.
- Remove carbon filtration during treatment, since it strips medication from the water.
Seachem KanaPlex and MetroPlex are available at Marine Concept Supply - order online or pick up at our shop in Wheeling, IL. Shop KanaPlex or MetroPlex, and browse more aquarium care products.

