I think I have columnaris

  • #1
I have a 30 gal tank. About a month ago I got a new Flame Gourami. It developed a raw patch on its side after about a week in the tank. I thought at the time that my rainbow shark was the culprit, as he is not always welcoming of new tank mates. I did think the wound was a little large for this though. About 3 days later the Gourami died.
About two weeks later I noticed that my pleco had a similar wound on the side of her head. It was white and after researching and looking at it again I realized it was also fluffy but more like a carpet than like cotton. I started treating the tank with Mylafix since the bottle says it treats cotton mouth, and this is supposed to be the same as columnaris. The Pleco stopped eating and I noticed a wound on my rainbow shark's head. At first I didn't know if it was just a scrape or not because it was small and he is always bumping into things and getting little scars on him. Then it turned red, is more like an open wound and now it has white fluff on it also. My Kribensis is also acting strange now but she has no physical signs that I can see.
I treated the tank with Mylafix for 7 days then did a 25% water change. During this time the wound on my Pleco turned a yellowish colour and starting shedding. Then it moved up onto her head and another small spot appeared on her side. She also looked like her skin was shedding or like there was cobwebs on her on the surfaces near the wound. The day after the water change the white fluff was back. I then started using Pimafix to see if it would be more effective. That was 2 days ago, today when I went to check on them I found my Pleco had died (RIP Flower).
My Rainbow shark's wound is raw and red with a little piece of white fluff on the edge. It only seems to be effecting my fish with no scales. My Pleco, and its only on my sharks head where he has no scales, which leads me to believe it's columnaris. My Kribensis is acting weird but I think she may be in egg laying mode, and my danios and rasborras are perfectly fine.

What do you think I should try next to rid my tank of this disease? I think maybe I should try some Kanamycin. Is there anything I should do to be sure I don't have a reoccurance? I have sand substrate, can this trap it? I want to get another Pleco but I'm afraid it will just get sick if I put it it there, how long should I wait before introducing a new Pleco?

I will add some photos of my Pleco before and after death and some pics of my shark.


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  • #2
Melafix is useless against columnaris, try maracyn II(erythromycin), kanafix(kanamycin), or Jungle Buddies Fungus Clear Tabs(furizolidone/nitrofurizolidone).
here is an article on columnaris:

Wait until no-one is sick, for starters, then quarantine the new pleco.
  • #3
Welcome to Fishlore!

I'm wondering why Melafix would be useless against columnaris. Personally, if going the natural route, I would use Pimafix in this case, or maybe a combination.
Also wondering why to use a fungal cure for a bacterial infection.

If going the meds route, I'm finding that a combination of Maracyn and Maracyn II, or some other combo med (likely to target both gram-positive and gram-negative bacteria) is the way to go, as a columnaris infection often opens the way for secondary infections.

There is likely another issue in your tank, though. Columnaris is one of those things that's often present, but rarely a huge issue. It's only when a fish gets stressed and its natural defenses start weakening that the bacteria manages to be damaging. Overcrowding, poor water quality, and other stressors can cause this type of issue. What are the ammonia, nitrite, and nitrate ppms? Is the pH stable? Is the temperature stable, or does it make a large swing when the lights go on?

Best to cure the problem, try and find the trigger, and then begin filling the tank back to capacity (note: a pleco doesn't belong in a 30 gallon tank. In my opinion, neither does a rainbowfish. Both grow too large, and the rainbowfish is too active, for that small of a tank).
  • #4
melafix is a near useless tonic (I refuse to call it a medicine) as is pimafix (those are of course IMO) especially when we are talking about a fast killer like columnaris. If you mess around with unproven cures your fish will die. Not sure if you have columnaris there or not but if you do use an antibiotic, I like kanamyacin mixed with nitrofurazone. The reference books will say to use oxytetracycline so that is another good option, the maracyns are another. PP can also be used to kill all the surface bacteria.
  • Thread Starter
  • #5
Thanks for the quick responses. I have done some research on the subject, but it is really hard to find a definitive answer to my questions. First was what is wrong with my fish? I have come to the conclusion that it must be columnaris, but I really am not positive. I've only had fish for a year now and they were kind of forced upon me since the house we bought had a tank built into the wall. The pleco came with the house so I don't know how old she was or even what type. I've had the tank for a year and had my Pleco, kribensis, and rainbow shark since then with no problems. I had some barbs that died of unknown causes about 2 months ago.

It's a Rainbow shark, not a rainbow fish, by the way. My water perameters are fine and they have been steady since the beginning. I do 1/4 water changes and vacuum every 2 weeks, and use cycle every time.

The next question was how to treat the problem, but since I'm basically guessing at the problem, choosing the right cure is not a fine art. I read what was written about diferent things it could be and decided it was a fungal infection, thus I tried using Melafix/Pimafix. Now after reading somewhere that columnaris tends to effect catfish in particular, I'm thinking it must be that. Plecos and rainbow sharks are both in the catfish family and they are the two being effected by it most.

Now I've tried asking for help here and I still am unsure of what to do, since everyone seems to have a different opinion on the subject ...sigh. That is the problem I found everywhere. I think I will try using Kanamycin next. My shark is getting worse and my kribensis is acting really odd now. I am afraid I'm about to lose my three fav fish. Already one down.
  • #6
Also wondering why to use a fungal cure for a bacterial infection.
If you look at the ingredients for the "Fungus Clear", you will see they are anti-biotic, not anti-fungal. Most of the time, "fuzzies" are bacterial, not fungal, but most people who see fuzzies on their fish assume fungus. Knowing this, pharmaceutical companies market their anti-bacterial meds as "anti-fungal", usually giving people the right cure for the problem, but perpetuating the myth that fuzzy=fungus.
Melafix is fine for slow-moving finrot, or nipped fins, but since Columnaris is capable of killing within 24hrs.(even though the strain tag is dealing with seems to be moving pretty slowly for this bacteria), something MUCH more substantial is usually required to save the fish, and sometimes even that isn't enough.
The krib "acting odd" could be either another symptom of columnaris, or responding to whatever is causing it in the first place.
The pleco looked to be a common, and REALLY didn't belong in a 30gal.
The rainbow shark doesn't belong in a 30gal. either(min. tank size 55gal.).
How you treat the problem is entirely up to you, as it depends on the resources available and how much time/energy you want to put into stopping the spread. Unfortunately, the best most aquarists can do with bacterial/fungal/internal problems is guess, since most do not have the laboratory equipment available to correctly diagnose diseases.
I hope your remaining fish recover!
  • #7
Ah, I am sorry your fish are ill. I dealt with it 6 months ago.....remove infected fish to a hospital tank and reduce temp to 75 as it thrives in warmer water and treat with Maracyn and Maracyn-two together. The lower temp slows it down so the meds work. I also used CopperSafe in combination with the above as it all started with ICH and raising the temp to 86 triggered it. I believe CopperSafe is listed as a treatment as well.

I wish you the best and I highly suggest you QT them.
  • #8
lipadj, while you are of course allowed to have your own opinion, I will strongly disagree with you about both Melafix and Pimafix. Not only have I seen them work, there is quite a bit of strong testimony from this forum that it works. We're talking about fish going from fin rot that has progressed down to the body of the fish to beginning regrowth within a day or two. Further, we know that both melaleuca and clove oil have medicinal value in other cases. Melaleuca oil has well-documented anti-microbial properties, and clove oil is both an analgesic and antiseptic.

If you look at the ingredients for the "Fungus Clear", you will see they are anti-biotic, not anti-fungal.

Good to know.
Lesson learned today: Jungle Fungus Guard=Antifungal, Jungle Fungus Clear=anti-bacterial
  • #9
Just to clarify, I have seen multiple members dealing with Columnaris try treating with melafix first, and it accomplished nothing. I know it works great with a lot of stuff, but for whatever reason I haven't seen this be one of them.
Oh, I forgot to mention, Welcome to Fishlore, Tag! bummer of a circumstance, but I hope you stick around even once this episode is over.
  • Thread Starter
  • #10
I went to the lfs and read all the packages of medication and decided that erithimycin would be the best course of treatment for what my fish appeared to have. The package has a picture of a spot that looks just like what my fish had and they called it simply "open red sores", and went on to explain that it was a bacterial infection. After treating my tank, my shark appears to be healing, and all my fish are back to acting pretty much normal, and eating. Now I really need to get a new algae eater of some sort. You really don't realize how much a pleco eats until you no longer have a pleco and you see how much algae there is and how fast it grows. I know a common pleco wasn't the right choice for my tank but it wasn't a decision I made for myself. Any suggestions on what I should get? Maybe a smaller type of Pleco?
  • #11
HI Tag, I'm glad you found treatment that seems to be working. I wouldn't add any fish at all until you haven't seen any signs of illness or strange behavior for a month, minimum (preferably 6-8 weeks).
Unfortunately, if your tank info on your profile is correct, I would say that your tank really doesn't have room for a pleco, even a smaller variety, especially as long as you have your rainbow shark. Ottos are a little smaller, but I really wouldn't recommend them, either, because they're incredibly sensitive to water quality and the way your tank is stocked could lead to unstable parameters. If you're having algae problems, you could add a few moss balls, or some fast growing plants, not necessarily to look nice but to absorb some of the nutrients from the water column and slow down your algae growth. Personally, I find snails to be excellent algae and water hardness control, but with the sensitive fish in your tank, I can't advise as to whether the additional bio-load would be advisable.

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