Erythromycin Powder – Bacterial Treatment for Ornamental Aquarium Fish

A 50 gram jar of Erythromycin Powder is approximately equivalent to 200 single-dose packets commonly sold in the aquarium hobby, making it a cost-effective option for aquarists who prefer purchasing in bulk.

Erythromycin is a treatment compound commonly used by aquarists when managing bacterial issues affecting ornamental aquarium fish. It is frequently used in both freshwater and marine aquariums when fish exhibit symptoms associated with bacterial stress.

This treatment is generally considered safe for use in aquariums containing invertebrates when used as directed.

Common Signs Aquarists Monitor

Aquarists may consider bacterial treatment when fish exhibit symptoms such as:

• Clamped fins
• Swollen or cloudy eyes
• Rapid or labored gill movement
• Patchy coloration
• Changes in swimming behavior
• Increased hiding or reduced activity

Common Aquarium Issues This Product Supports

Aquarists commonly use erythromycin-based treatments when managing issues such as:

• Columnaris-type infections
• Fin and tail deterioration
• Mouth infections
• External bacterial issues affecting aquarium fish

Suitable for use in freshwater or marine aquariums.

Optional Use for Cyanobacteria

Some aquarists also use erythromycin-based treatments in very small doses when addressing persistent cyanobacteria outbreaks, typically after other aquarium maintenance approaches have been attempted.

Treatment Dosage

Dose 250–500 mg (approximately ¼ teaspoon) per 20 gallons of aquarium water every 24 hours, performing a 25% water change prior to each dose.

Continue treatment for 10–14 days. If no improvement is observed after 5 days, aquarists often reassess the underlying cause before continuing treatment.

Cyanobacteria Dosage

Dose 200–250 mg per 10 gallons. In many cases a single treatment is sufficient. If needed, dosing may be repeated following a 25% water change. Manual removal of remaining cyanobacteria and improved tank maintenance are recommended to help prevent recurrence.

Important Use Information

All products in this section are intended for ornamental aquarium fish only and are not intended for human consumption or for fish used for food production.

By placing an order, you acknowledge and agree to our Ornamental Fish Medications Guidelines:

This product is dropshipped directly from our trusted supplier to ensure quality and proper handling. Availability may vary depending on supplier inventory.