Broad-spectrum imidazole antifungal — especially effective for external skin and surface fungal infections in ornamental fish.

Antifungal — not an antibiotic. Ketoconazole targets fungal organisms, not bacteria. Signs of fungal disease include white or gray patches, fuzzy growths on the skin or fins, scaling, or discoloration around wounds. For bacterial infections, browse our fish antibiotic collection.

Why choose Ketoconazole? Ketoconazole belongs to the imidazole antifungal class and is known for its particularly strong activity against external, skin-surface, and dermal fungal infections. While both ketoconazole and fluconazole treat fungal disease, ketoconazole has broader activity against a wider range of fungal species including dermatophytes and Candida. It is the preferred choice when fungal lesions are visible on the skin, scales, or body surface — as opposed to internal or systemic infections. Also commonly known as Nizoral.

About This Product

Ketoconazole is a broad-spectrum imidazole antifungal medication effective against a wide range of fungal organisms affecting ornamental fish. Like fluconazole, it works by inhibiting ergosterol biosynthesis in fungal cell membranes — but ketoconazole acts on a broader range of fungal enzymes, giving it stronger activity against external, dermal, and surface-level fungal infections including dermatophytes, Candida species, and other skin-dwelling fungi.

Each tablet contains USP-grade Ketoconazole 200mg in a 30-tablet count. Ketoconazole is the go-to choice when fungal disease is visible on the skin, scales, or body surface of the fish — making it the preferred antifungal for external presentations. It is effective in both freshwater and saltwater tanks.

Also commonly searched as: fish ketoconazole, ketoconazole for fish, fish external fungal treatment, nizoral fish antifungal, fish fungus ketoconazole, imidazole fish antifungal, aquarium ketoconazole.

Commonly Treats

• External skin & scale fungal infections
• White or gray patches on skin/scales
• Dermatophyte fungal infections
• Candida species infections
• Fungal lesions around wounds
• Scaling & skin discoloration (fungal)
• Surface-level fuzzy or velvety growth
• Fungal infections unresponsive to other treatments
  

Directions for Use

1. Determine your dose: Use one 200mg tablet per 50 gallons of aquarium water.
2. Dissolve the tablet in a small amount of aquarium water before adding to the tank. Stir until fully dissolved.
3. Add directly to your aquarium, pond, or hospital/quarantine tank.
4. Repeat every 24 hours for 5–10 days. Do not exceed 10 days of continuous treatment.
5. Perform a 25% water change each day before re-dosing to maintain water quality and reduce medication buildup.

Product Specifications

• For ornamental fish use only. Not intended for use in fish raised for human consumption.
• Not for human consumption. Do not ingest. This product is sold for aquarium fish treatment only.
• Keep out of reach of children. Store in a cool, dry place away from children and pets.
• Do not exceed 10 days of continuous treatment.
• Remove activated carbon from your filter before treatment — carbon will absorb the medication and render treatment ineffective.
• Not effective against bacterial infections. Ketoconazole targets fungal organisms only. If a bacterial infection is also present, a separate antibiotic treatment may be required alongside antifungal therapy.

Label & Usage Disclaimer: Please read and follow all label directions before use. Product descriptions and usage instructions shown here are taken directly from the manufacturer’s product label and information provided by Montana Aquarium Supply. These statements do not represent the views or recommendations of Pittsboro Pet Supply or Pittsboro Feed. Made in the USA. Distributed by Montana Aquarium Supply – Billings, MT.