Bacterial and fungal fish infections don't all respond to the same medication - gram-positive and gram-negative bacteria need different antibiotics, and true fungal infections need something else entirely. Fritz's Maracyn line covers all three.
Matching Medication to Infection Type
- Maracyn - a broad-spectrum antibiotic (erythromycin) that dissolves gradually in water, primarily effective against gram-positive bacteria.
- Maracyn Two - a broad-spectrum antibiotic (minocycline) absorbed through the skin, primarily effective against gram-negative bacteria, with some effectiveness where Maracyn alone falls short.
- Maracyn Oxy - a fast-acting, non-antibiotic liquid treatment for true fungal infections, safe for fresh and saltwater systems and most invertebrates.
Why the Distinction Matters
Treating a gram-negative bacterial infection with a gram-positive-targeted antibiotic (or vice versa) wastes treatment time while the infection progresses. Correctly identifying - or at minimum, having both options available - matters more than defaulting to whichever product is on hand.
How to Use Them
- Use in a quarantine tank whenever possible, rather than treating the main display directly.
- Complete the full treatment course even if symptoms appear to improve early.
- Remove carbon filtration during treatment, since activated carbon strips medication from the water.
Fritz Maracyn medications are available at Marine Concept Supply - order online or pick up at our shop in Wheeling, IL. Shop Maracyn, Maracyn Two, or Maracyn Oxy, and browse more aquarium care products.
