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Columnaris Treatment Information

Columnaris Treatment Information

This is an interesting and Informative Post Found While Searching For More Information about this disease

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This is a post found on another Blog Site’s Disease forum that accounts someones experience with this infection. I hope this will help someone else who finds themself in a similar situation. Unfortunately, I had and awful outbreak of columnaris. I have spent the past two weeks researching and trying to fight this tough disease. through this process, i have come to realize that there is A LOT of misinformation about this bacteria, what it looks like at different stages, what causes it, and how to treat it. The lack of information often leads to a delay of treatment or improper treatment which results in catastrophic fish loss. My own background in biochemistry lead me to do a bit of research on this. I hope some of the lessons i’ve learned through experience and reading will help someone else who happens to face this. There are 4 (yes FOUR) different documented strains of columnaris found in aquarium settings. strain 1: this strain has been known to wipe out an entire fish stock in 24 hrs. in most cases there are NO OUTWARD SYMPTOMS. this strain is highly virulent and has a high affinity for attachment to gill filaments. from there it enters the blood stream through respiration where it creates a systemic infection. organ failure is rapid usually starting with the kidneys. A fish that has succumbed may look normal in coloration, or may appear to have bloody streaks along it’s fins and body. a closer examination will show a discoloration and degradation of gill tissue (a bloody reddish brown). In most cases, the disease can only be done by a necropsy. strain 2: strain 2 is highly virulent and also results in high mortality rates. in this case deaths are chronic and can span for several weeks until the entire stock is wiped out. the bacteria has a highly developed rhizoid which allows it to attach to the tissue of the fish as well as glass, plants, rocks, substrate, left over food etc. in higher hardness/ph it has the ability to form long filamentous colonies that are visible to the naked eye. this is usually mistaken for fungus. it is a transparent white that moves with the current. fish may or may not have have the classic lesions. many will die from what appears to be hemorrhagic septicemia. As this strain becomes more established, fish will start to develop the classic white, ulcerated lesions around the mouth, fins, and dorsal line. There is usually significant organ damage by the time a fish shows outward symptoms. As the infection progresses, the fish may appear to have lumps on the body or small red spots around the head and gill area. as the gill tissue dies, the fish may still eat and swim, but will generally stay near the surface, airstone, or filter outflow. Infected individuals will eventually lose their ability to circulate body fluids resulting in a swelling around the head and abdomen. the eyes may even appear to be sunken in. most fish will die within 48 hrs of showing outward symptoms. *strains 1 and 2 are more prevalent in warmer tropical environments. the optimal temp for growth is around 85*f making this form a large threat to discus keepers despite the more acidic conditions that these fish live in* strains 3 and 4: these strains are not as deadly and usually result in the classic white lesions. fish death may take a substantial time. one of these strains seems to lack a rhizoid and is unlikely to attach to glass etc. these strains are often easier to treat since they are slower acting and lack the attachment ability that the 1/2 strains have.These strains tend to survive in cooler temps making them a bigger threat to goldfish, koi etc. columnaris is a gram negative AEROBIC bacteria and therefore must be treated by a gram negative antibiotic for AEROBIC bacteria. this is why metro and maracyin 1&2 may not work despite being gram negative. Aerobic bacteria need oxygen to survive, so this is one bacterial infection that CAN severely impact CLEAN aquariums. Increasing flow/oxygen levels will not kill this bacteria and in my case the colonies grew the largest right around my filter outflow and air stone. Columnaris also tends to prefer hard water with a higher content of calcium and magnesium due to the redox potential that harder water creates. Harder water with a higher ph tends to favor bacteria growth in general and columnaris is no exception. Despite this DO NOT try to alter your ph for treatment. this will only further stress your fish and result in more death. this bacteria can remain alive in water columns for up to 32 days without a host therefore this organism may be present in small numbers at all times. it needs a vector in order to become parasitic. in my cases it was a new fish that had died and i was unable to find it early enough. this combined with the fact that i have a planted aquarium seemed to make this bacteria explode. i first noticed the colonies on the glass and thought it was hydra or snail eggs from new plants, but the day after trimming my hair grass it had exploded into a massive white fluff everywhere! my initial search lead me to a fungus. i cleaned it out and thought that would be the end. then the deaths started. one after the other. the first few did not have the classic lesions which left me stumped. i read for hours and tried basic treatments for all sorts of things due to lack of proper information. i finally broke down and started reading research papers and doing a bit of my own experimentation. this led me to the proper diagnosis and understanding of this disease.

This is what has worked best for the author… Columnaris does not survive in salt solutions of 1% or higher. this makes salt a great first line treatment for less severe cases. dips are great for infected fish, but in some cases treatment of the entire tank is a must, and i have planted tanks! i then decided to go with nitrofuran for the water column, kanamycin medicated flake for internal infection, low does of salt, and h2o2 spot treatment for the white fuzz on my plants. any oxidizer will work wonders due to it’s ability to KILL the bacteria directly while the antibiotics inhibit growth and reproduction. this combination is the only thing that has given me the upper hand. i do large water changes before each dosing and manually removed the dead fluff. Remove any dead fish asap to prevent surviving fish from picking at the infected individual resulting in internal infection. * there are a few important points to note when treating with antibiotics*:
1) always finish the full treatment to avoid creating resistant strains
2) research compatibility of antibiotics before mixing
3) certain antibiotics work better at a certain ph.
Maracyn is a perfect example. this medication will not work well at a higher ph. it will quickly become inert which is an other reason columnaris is hard to treat with this medication.

The following are a few tips on commonly used antibiotics:

Erythrommycin: less effective at higher ph and does NOT treat gram negative bacteria. this makes maracyin a poor choice for treating columnaris.
Tetracyclines minocycline: broad spectrum antibiotics that may or may not treat the early stages of columnaris. bacteria seem to be able to easily build a resistance to these medications which is why maracyn 2 may work at first but is usually followed by a larger more resistant outbreak shortly after treatment has ended.
Triple sulfa and other sulfa based medications: can be highly effective in the early stages of columnaris. more advanced stages may build a resistance to this medication resulting in similar problems as maracyn 2.
Kanamycin: a great broad spectrum antibiotic to use against hard to treat infections. it works best at a higher ph and can therefore be used in the water column for anything over a ph of 7 without fear of it becoming inactive. for tanks with lower ph, kanamycin can be fed as a medicated food and will be just as effective for internal infections. CAUTION must be used because this is one medication that can have catastrophic effects if overdosed. It will also affect your good bacteria as well so some may want to use a medicated flake regardless of ph, but do keep in mind that kanamycin is highly water soluble so any uneaten food must be removed PROMPTLY if you do not want it in the water column.Nitrofuran based medications: furans are the best choice for columnaris especially when combined with kanamycin. they are slightly affected by ph and tend to do better in a lower ph setting. This medication can still be used in a higher ph if water changes and redosing are preformed on a regular basis. another advantage of nitrofuran is the fact that most bacteria are unable to acquire a resistance to it and it doesn’t seem to be as harsh on fish as kanamycin (although caution must still be used with any medication!). a down side is that it may or may not have a negative effect on plants, so use caution in planted setups.
Acriflavin neutral: another good bactericide that can be used to treat mild to moderate infections. it will also eradicate secondary infections my true fungus. it has the potential to kill plants so use caution!
Oxidizers: oxidizer play into the redox potential of the aquarium and will directly kill any organisms that are topical or in the water column. this is why it’s a great spot treatment for ulcers on fish and living colonies in the aquarium. bleach, hydrogen peroxide, potassium permanganate, and acetic acid (vinegar)are all oxidizers. do not use bleach directly in the water column. this is better used to sanitize objects outside the tank if followed by a good rinse and a dip in some dechlorinator. potassium permanganate can have adverse effects on inverts and other sensitive species so caution must be used and always follow directions! Acetic acid (vinegar) is a great choice to disinfect the area around the tank (i.e. external glass or the stand/table that hold the tank). Oxidizers may also interact with the effectiveness of medications so do treatments right before water changes and follow with re-dosing of antibiotics.
Hydrogen peroxide worked wonders for me, so i will outline this method:
Hydrogen peroxide: 2-3% solutions can be found for cheap almost anywhere. i used a syringe for spot treatment. from my research, i have found that you can use up to 2 ml per gallon of ACTUAL water in your aquarium (therefore you must make adjustments for the capacity with decorations). I did not use that much. i started with 1/4 of the aquariums capacity and increased from there, but still did not reach a maximum dose. it is best to turn off the filter (you can leave an airstone running if needed) and squirt the h2o2 onto the fuzzy spots before changing the water. it may or may not bubble depending on the o2 concentration in the tank. allow it to stay on the spots for 20-30 minutes under close supervision of your fish. use a toothbrush to manually remove the fuzz and then do a 50% water change. My fish and snails did not show any ill effects of this low dose treatment, and it was one of the few things that quickly killed off the fuzzy colonies. peroxide is a strong oxidizing agent so never leave fish unattended under treatment. *SALT* as mentioned earlier, salt is a great first line of treatment or used as a dip for more experienced keepers. All strains of columnaris will fail to thrive in salt solutions of 1% or higher, and some strains will die off at as low as .5%. Research proper bath and dip techniques before using, and keep in mind that the vast majority of plants will not survive for long in any type of salt solutions, so use modestly in planted tanks.
Catfish can also be highly sensitive to salt as well.


Gram positive and anaerobic antibiotics, increasing flow/oxygen levels, melafix/pimafix, raising the temp (this may actually make it worse!!) metro, other parasite treatments, and in the case of internal infections most water column only treatment will have little if any effect. it’s important to attack severe infections as soon as possible and many of the usually suggested medications will not work! This bacteria is extremely contagious and can be easily spread between tanks. Sterilization of equipment is a must if you have multiple tanks that share maintenance items. It is also spread through fish food, so be careful when you feed your fish as well. and while this seems like a no brainer, always wash your hands with an antimicrobial soap after touching the infected fish/tank! Prevention is the best method! Keeping your tanks clean and healthy while implementing good quarantine practices will help prevent most diseases. Sometimes things go wrong despite our best efforts. in this case early treatment = easy and effective treatment!!! Once columnaris becomes established in a tank, it’s a long hard road to recovery. I hope this information will help someone else who is faced with this evil infection!

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