best tx for columnaris?

[NancyD]

I recently removed a rasbora with columnaris from my sid & striata tank. All the same fish have been in the same 75g since adding denisoni barbs 9 months ago or so ago. I noticed a couple less rasboras than I thought were in there .

The tank has been set up for ~2.5 years, 75g light -medium planted

Nitrates 10ppm or less often 0, ammonia & nitrate both 0, pH 7.0

Weekly water change ~25-40%, trying to do smaller amts twice weekly but not consistant yet

Aqua Clear 70 HOB & Rena XP3, AC cleaned every week or 2, XP monthly

Fish- 6 2+inch b.striata, 9 sids 1.5-2 in (lost 1 ~1.5 years ago), 10 harlequin/espei rasboras (had 12?, not sure), 2 p.denisonii 3 in, 2 SAE & similar ~4 in., 1 MIA oto (lost 2 ~2 years ago), 5 red tailed rasboras (lost 1 ~ year ago)

Eco complete substrate, surface vac with water change

This tank has a chronic cyano problem I attribute to nitrate drop & very inconsistant ferts

The rasbora that I euthanized had gray along it's dorsal fin on both sides, narrow bands & the same where the pectoral fins attach to the body. It was swimming slow & I don't think it was eating, not sure.

I think it's time for an antibiotic, I've not had much luck with Maracins in the (long) past. I'm thinking maybe kanaplex. Many different antibiotics are suggested online, what do you think? No other fish are showing signs at this time but these are among my favorites.

[chefkeith]

I wouldn't treat the main tank with antibiotics, especially if no fish are sick. IMO, You should only use antibiotics in quarantine tanks, otherwise you might promote stronger and more resistant strains of bacteria.

There will always be some level of columnaris bacteria in your tank. The fishes immune system, if the fish is healthy, will ward off bacteria, diseases, and infections. Usually only weak, injured, or older fish will be vulnerable.

If you want to lower the free floating bacteria levels and prevent cyano breakouts, then I suggest using a UV sterilizer instead.

[shari2]

Nancy, are you positive it was columnaris? Do you see symptoms on any of the other fish?

It sounds like you have a valuable set up there and I'd second the suggestion for a UV sterilizer before you go with antibiotics, especially if you're not seeing symptoms on your other fish. It will pay for itself if you consider possible fish losses and costs to treat a 75g tank.

[NancyD]

I have doubts about the health of 3 other rasboras & the crossocheilus (the non SAE) has long term issues but nothing that says columnaris to me, yet anyway. I waited to have a good look this am.

Two rasboras have a pale grayish look along it's spine unlike others, hard to tell with 2 species & a color variation. 1 has a small whitish area at the bottom of the gill plates on both sides that's new I think.

The non-SAE I've had for almost 3 years. When small he looked exactly like a SAE but his fins have gradually turned yellow. It's problem is it's mouth doesn't close properly. I'm not sure if this is from an injury or a disease process. I noticed it ~2 years ago & it's gotten a little worse. It is able to eat but not as well as it used to & has lost weight. There is no redness or obvious growth. It doesn't compete as well for food as it did now that the barbs & other SAE are big.

The loaches seem fine as far as I can tell although I can never see a 9 sids to count them. The fattest, darkest female sid is either MIA or no longer gravid or as dark, there is 1 with a similar friendliness I hope is her.

Thinking back there was a rasbora 2-4 months ago with similar pale gray or whitish patches that I also euthanized. I was very busy & details are sketchy. No red sores that I recall. IME once they show several big patches the is no effective treatment.

I know columnaris can be present but it seems maybe the last few months to have gotten worse if the missing fish are recent unnoticed deaths. Of course unfound bodies can lead to many bad things.

I had a quick look for uv vs columnaris but results were, as usual on the web, conflicting. I'm worried that the bacteria may be effecting at least some of the fish themselves already & of course the uv can only kill bacteria etc in the water column. That's why I think it's time for an antibiotic.

[chefkeith]

Doing small daily water changes for awhile would help. Be extra careful when adding or removing fertilizers. Changing the water chemistry stresses the fish, possibly making them weaker, and more prone to bacterial infections. A major contributor to bacterial growth is Iron. If you are adding any kind of iron supplement to the water, that could be promoting bacterial growth.

Sorry, but I don't like to recommend the use of antibiotics in a main tank. Also it's not going to fix the problem of why the fish are getting sick. IMO, sick, weak, or injured fish should be quarantined and treated where they can be easily monitored.

[shari2]

Have you tried the flashlight test on the ones with the patches? After lights out, see if you can see any kind of sheen on the bodies of the fish while the light is shining on them. If so, you may be dealing with velvet, not columnaris.

have you seen any flashing? anyone showing signs of labored breathing?

if you do decide to treat I'd recommend Kanaplex (or anything with kanamycin) as it is absorbed through the skin, so even fish off their food will benefit.

[NancyD]

Keith & Shari thanks for the help

I haven't seen any flashing lately though I have periodically. I usually think it's a water quality issue & do a water change. I will check with a flashlight, I have never found velvet on fish.

I also have diatoms & green spot type algae that don't really bother me . My husband was home on vacation & likes to wake up the tanks earlier than normal so he can see the fish more so there was more algae. So there was more "stuff" in the tank than sometimes.

I rarely use ferts usually an occaisional NPK tab or bit of micros w/iron tab by the crypts. My tanks are not "pretty plant" tanks. I have removed some of the rotala with dead? algae, an on going battle.

I'm going to try more frequent water changes for a while but I think I'll also order some kanaplex & research uv. Any suggestions on uv filters? Watts , flow rate etc? I know nothing about them.

[NancyD]

I looked a few times last night with a flashlight, hard to find small fish. Eventually I did see the 2 rasboras with grayish top line, no goldish speckles but the gray was more dull. Can't find the 1 with the gill spots...I'll keep looking.

Bad news though the "real" SAE, not the open mouth one, has a dull gray area between it's eye & gill the diameter of a pencil. Looks like excess slime coat in that area. He seems a bit less active. It's possible he slightly injured himself trying to escape the flashlight, a big unseen fish did a splashy jump.

Loaches & barbs still look good, loving the daily water changes

[NancyD]

Update- I am tired of water changes but it seems to have helped some & the loaches love it. The 2 rasboras with the dull gray along the dorsal base look a bit better.

The 1 with the gill base spots got smaller but whiter & fuzzy but seem to be going away, on 1 side anyway.

The SAE with the gray excess mucus-ish area between eye & gill has it on both sides now. I don't know what this is.

I cut back to every other day water changes but twice a week is going to have to be enough, snow shoveling is tiring me out too. You'd think be I'd be skinny & have lots of muscles by now