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Further Recommended Reading:
Fish Diseases | How to Treat Sick Fish
TRUE Aquarium UV Sterilization; How to Use a UV-C Sterilizer

Aquarium Information
-A great source for current aquarium information that is updated regularly as new research become available.

Aquarium Fish Merbromin External Columnaris-Bacterial Treatment



AAP Merbromin for Aquarium, Pond Fish Wound treatment, Columnaris Merbromin is a lessor known product to many newbies in the hobby due to difficulty in obtaining, but to those who have been in the industry and hobby for a long time its benefits are well known.
In fact this is a product NO SERIOUS AQUARIUM KEEPER SHOULD BE WITHOUT, especially when one considers its low costs and benefits

Merbromin (AKA Mercurochrome) is a topical antiseptic often used for minor cuts and scrapes in people. Merbromin is an organomercuric disodium salt compound and a fluorescein.
It is useful on external infections because of its permanence, and lethality to bacteria, in particular Columnaris.

Part of the difficulty of obtaining this product was concerns over its mercury content, however due to the low cost versus high costs of producing studies to disprove these allegations (which were never proven), most production has stopped for human use.

External Columnaris treatment using Merbromin from American Aquarium

HERE IS FURTHER INFORMATION (Courtesy American Aquarium):

  • AAP/Aquatronics Wound Control/Merbromin is a swab or paint-on disinfectant with PVP emulsifier for: wounds, scrapes, and abrasions as well as opportunistic bacterial infections that often result from these problems.

  • A topical antiseptic and oxidizer used for injuries, exposed wounds & open sores (with both bacterial and fungal infections), and exposed multi cell parasites such as Anchor Worm.
    Due to its anionic character, it is often an excellent choice for exposed EXTERNAL bacterial or fungal pathogens (including some parasites or at least secondary infections there of). However for this same reason if much living tissue is exposed or for gills, Methylene Blue would be a better choice.

  • A scrape against rocks or a bite on the scales can result in a serious infection. The simple process of catching the fish and painting the affected area will often prevent more serious problems or aid in an in tank or hospital tank treatment with antibiotics for more serious infections.
    Wound Control should also be used after any operation such as extraction of visible parasites.

  • All Fish safe assuming the fish can be safely handled without causing further injury.

  • USE:
    Net the fish. Gently use the net or hand to hold the fish in place (applying Req-Q, StressGuard or similar to your hand or net prior to application may be helpful). Apply Wound Control through the net or use a cotton swab to apply directly on the area.
    Place the fish in a hospital tank or quarantine box if possible & treat in tank if needed (Consider following the application of Wound Control with a Medicated Fish bath too). In a calm protected area the fish heal faster and less fish stress will occur when catching the fish.

AAP Merbromin

Further Reading:

Suggested other aquarium information resources & products:

Fish Diseases, How to Treat Sick Fish
Fish Diseases | How to Treat Sick Fish

Freshwater Aquarium Care
Freshwater Aquarium Care

Aquarium Medications, Use of replacement UV Bulbs for disease prevention
Replacement Aquarium/Pond UV Bulbs

Replacement of your UV Sterilizer's UV Bulb/Lamp every six months with a true level 1 capable bulb is a MUST for optimum disease prevention and aid in Redox balance.

Aquarium UV Sterilization, sterilizer use, heater information
Aquarium/Pond UV Sterilizer Use

This article covers many aspects of Aquarium & Pond UV Sterilization from how, why, facts, myths, and maintenance including the importance of changing UV Bulbs regularly.