Betta Fin Rot; Treatment and Prevention.
This applies to most ALL fish, but since I get so many emails and questions pertaining to Betta Fish, this is the main subject of this article.

Updated 5/12/13

Let me first start out by noting that "Fin Rot" is a generic term that does not define any one disease, rather there are many causes of this Symptom; of which Fin Rot is better described as a symptom with more than one cause.

Often Fin Rot is brought on by injury or ammonia/nitrite poisoning, so when one considers either treating or preventing the symptom of Betta Fin Rot, these are first places to start. As well opportunistic bacteria such as Columnaris, Pseudomonas, or occasionally Aeromonas can result in fin rot (often taking advantage of fish weakened by other causes). See a picture further into this article for a picture of a Betta with Columnaris induced fin rot.

Here are several points, generally in order of importance to check if your Betta has or continues to contract symptoms of fin rot:

1. Make sure your tank/bowl is as close to 0 in ammonia or nitrites at ALL times; if your water starts at 0 ammonia but by the end of the week on "water change day" the level is up to 1 ppm, this is unacceptable!
   I cannot emphasize how often I have traced back cases of Betta Fin Rot (of of more than one bacterial pathogens) to ammonia levels that are constantly in flux!
   
   Personally I recommend a small Sponge Filter if at all possible for a healthy bio filter.
   
   However I realize that many Bettas are kept in small tanks/bowls where this is not possible, but even then keeping a small amount of Matrix Bio Media (or similar high pore bio media) in a medicine/prescription bottle with holes punched/drilled in the sides to allow water through the container, while not allowing the Betta to drag his/her delicate fins across any potentially abrasive surfaces. Please click on this picture to enlarge.
   
   Please also read: Aquarium Nitrogen Cycle



2. Water Chemistry other than Nitrogen Cycle (ammonia, nitrites, etc.) parameters.
   This is an area where I think many misunderstandings/mistakes are made along with ammonia spikes.
   Often in emails, forums, and my previous aquarium maintenance "Fish Doctor" house calls, I have found that Betta keepers (& other fish too) tend to worry about pH and use products attempting to "nail down" "hard" ph numbers while ignoring KH and positive mineral ions.
   The KH; which are alkaline buffers plus acid buffers are more essential than a specific pH (within reason as obviously a pH of 5 or 9 is not acceptable).
   These buffers maintain a stable pH and just as importantly carbonate hardness (KH) maintains a healthy nitrogen cycle as without these carbonate buffers your nitrifying bacteria cannot thrive and you end up with even more dangerous ammonia spikes!
   Generally speaking I would recommend a KH of 50-150 ppm (for Bettas) and your pH will be just fine for Bettas as long as it is STABLE at some number between 6.5 to as high as 8.2 (reference: Betta Habitat)
   
   Simply put, do not chase pH in an attempt to find the perfect pH. Find an acceptable KH and stick with it, even if the pH is higher than desired as a bouncing pH can cause more disease inducing stress than the actual pH number.
   
   The second part of Aquarium Chemistry (GH, KH, pH) that is also important (if not more so) and also missed by many is the need for positive mineral ions (electrolytes) in the water for a healthy Betta (or other fish) immune system.
   Often Betta Keepers will use RO, Drinking, or Distilled Water without adding back these essential elements. Even when tap water is used, often products such as "pH down" or "7.0" are employed, which when used alone can drive out some essential mineral ions.
   
   The use of too much incorrectly treated RO water can result in Redox stress, although the flip side is attempting to make up for neglect in adding positive mineral ions too quickly which also can add stress (both are similar to rapid pH changes).
   Another chemistry stressor is oxidative stress from un-treated tap water or too high of a Redox reading (constantly over 300mV).
   Any of these before mentioned Redox can lead to a Columnaris infection that can then lead to a case of Columnaris induced fin rot (which is often a much more difficult to treat fin rot when compared to a minor cases of simply ragged fins).
   
   Best is a balanced approach which includes actually maintaining GH (of over 100 ppm) if only to maintain these essential mineral ions (cations) which are depleted quickly even though your GH test kit shows a higher GH (please read the GH section of Aquarium Chemistry; Gh)
   
   Using products such as driftwood fragments, Peat, Pillow Moss (AKA Frog Moss) or Atisons Spa for their Indian Almonds leaves to naturally provide a tannin acid buffer along with Alkaline Buffers such as SeaChem Alkaline Buffer is a must for use with RO water and even some tap waters.
   Then the use of products such as Wonder Shells to provide a constant supply of positive mineral ions is very helpful, if not essential in small tanks/bowls to aid in constant replenishment (water changes help too).
   These mineral blocks come in sizes small enough for a fish bowl and can be used with Pillow Moss or even driftwood fragments to act as an acid buffer.
   Pillow Moss can be placed in aquarium filter bags (such as by Lees) to prevent it from coming apart if used directly in the aquarium.
   
   Please read Aquarium Chemistry, SE Asia Water for much more; a must read!!



3. Injury is another potential issue with Bettas; Make sure you have smooth decorations (such as marbles). Also watch for reflections that may make your Betta chase his tail (like a dog!); in fact if your Betta is dealing with symptoms of tail rot, I strongly recommend covering your tank/bowl with a towel or similar for a calming effect that can and does help.



4. One of the first actual treatments I would consider is a Medicated Fish bath that includes salt (Sodium Chloride), Methylene Blue, and possibly a mix of antibiotics Nitrofurazone and Kanamycin.
   The methylene blue is very helpful for fin rot and ulcerations caused by ammonia or nitrite poisoning.
   However Methylene Blue is not as a strong an antibacterial for gram negative bacteria, if these baths are ineffective, I would switch to Potassium Permanganate (which is a stronger oxidizer). Potassium Permanganate should be used only with salt and no antibiotics.
   Also be careful about over dosing with Potassium Permanganate as it is a strong oxidizer where you are essentially oxidizing the "fin rot" more than the fish!
   
   Potassium Permanganate or Hydrogen Peroxide can also be used as a "swab" on damaged fins or other areas of infection.
   
   See this Aquarium Answers post for more about how to perform such a bath or swab:
   Fish Baths



5. Next, assuming your Betta actually has a bacterial infection you may have to start an in tank treatment. The most common bacterial causes of fin rot being Columnaris & to a lesser extent Aeromonas Bacterium.
   Pseudomonas bacterium may be the cause of mild fin rot infections in which the fish generally only display frayed fins and black fin edges.
   
   Please read Columnaris in Aquarium Fish and/or Aquarium Aeromonas, Septicemia, more first and consider the suggestions and treatments there in.
   
   The picture to the left displays a Betta with Columnaris induced Fin Rot, please click to enlarge (though not all fin rot is caused by Columnaris)
   
   A strong "in tank" treatment would be the before mentioned (for fish baths) Nitrofurazone and Kanamycin combination.
   
   Another alternative (which can also be used in baths) is Triple Sulfa. This is an excellent broad spectrum alternative to the Kanamycin/Nitrofurazone combination and although generally not as "strong" a treatment, it is occasionally effective when the Kanamycin/Nitrofurazone combination is ineffective. As well Triple Sulfa is generally less harsh on the fish and is a good choice for generally less difficult cases of fin rot with Pseudomonas as the bacterial cause.
   
   If this is a serious infection, most often these are caused by gram negative bacteria and treatment with primarily gram positive antibiotics such as Tetracycline or even Maracyn 2 (to a slightly lessor extent) will often be futile as the vast majority of aquarium bacterial infections are gram negative.
   Columnaris, Pseudomonas, & Aeromonas are ALL Gram negative so if someone suggests a gram positive treatment for your fish' fin rot, it is not going to be effective (if it is your fish has another disease)!!
   
   Please read Aquarium Medications; Page One
   
   If this is a minor infection, often just the baths and/or a mild in tank treatment may help (assuming correct water parameters as addressed earlier in this article). Products such as Medicated Wonder Shells or Pimafix/Melafix can help (with Melafix use with Bettas, a pH over 7 and GH over 100 is a must; see Melafix Dangers)

Other Suggested Reading is:
*A Healthy Aquarium, Disease Prevention
Even suggested steps such as the use of a UV Sterilizer should be considered if at all possible, although usually not practical for the average Betta owner. However with larger Betta Breeders or similar multi Betta specimen tanks with dividers, the use of a UV Sterilizer may be practical. Make sure is you are able to employ a UV Sterilizer that you change your UV bulb every six months for optimum efficiency.

Other Recommended Reference Sites

-A useful source for current Aquarium Information and Resources (Pond too). Basic and in depth articles from Aquarium Lighting, Filtration, Fish Nutrition, UV Sterilization, Ich, Pond Care, Nitrogen Cycle, and much more. Well researched and up to date aquarium and pond articles, answers, help, and links. Based on 33 years Professional experience & research in Los Angeles and now in Oregon. This Aquarium and Pond Information resource is a must read for any aquarist serious about current aquatic information and articles

For a friendly, Knowledgeable, aquarium forum with in a family atmosphere, Aquarium Forum; Everything Aquatic & Board is an excellent place to go for information, help or simply to share your love of the aquarium and pond hobby and help others. A superior place for information over such places as Yahoo Answers

FISH AS PETS; Articles and commentary of Interest to the Aquarium Hobby; Such as Parasite Retailers, Planaria & Detritus Worms in Aquarium, Melafix Dangers, & Celestial Pearl Danio, Galaxy Rasboras

Labels: Atisons Spa, Betta, Betta Disease, Betta Gh, Betta pH, Calcium, Fin Rot, High Ammonia, Indian Almond Leaf, Mineral Ions