Fin nipping (or finrot) on a new fish -- quarantine from the quarantine?

[tuonor]

Picked up six Kubotai rasboras last week from my LFS.  Drip acclimated them before adding them to a 5.5 gallon quarantine tank, treating them with ParaCleanse as a precautionary measure.  I also have ich-X and an antibacterial but decided to treat just for internal parasites initially and observe.

About a week into quarantine, seeing one of the Kubotai has a damaged anal fin.  Not sure if this is from nipping or finrot but thinking back, my daughter had noticed a white stripe on one fish's anal fin when we got them home, just couldn't discern any damage until now.,,the translucent fins are so tiny.

We have kanaplex on hand.  Should I first try a salt treatment as a gentler approach or go strait to the antibacterial?  His fins aren't clamped and he is swimming around with the rest of his school.  But his belly does seem to be less full than the others.

If I do use kanaplex, would best practice be in the QT tank with the others or in a separate isolation tank?  Seems like it would be additionally stressful to net / move him to a new container...OTOH want to minimize any risk of infecting the others and maybe they should be treated preventatively anyway.

QT tank was not an established tank has cycled filter media from the main tank and is reading zero ammonia and nitrite.  Nitrate is ~5ppm.  Just did a 25% water change after the ParaCleanse treatment. 

Thanks in advance!

Edited September 5 by tuonor

[Colu]

Am not seeing any Reddening to the fins that would indicate an active infection looks more like an injury to me What I would do is add some Indian almond leaves as they have antibacterial and antifungal properties you might have to add one leaf per gallon to get a beneficial effect and monitor @tuonor

Edited September 6 by Colu

[tuonor]

On 9/5/2024 at 8:01 AM, Colu said:

Am not seeing any Reddening to the fins that would indicate an active looks more like an injury to me What I would do is add some Indian almond leaves as they have antibacterial and antifungal properties you might have to add one leaf per gallon to get a beneficial effect and monitor @tuonor

Got it, thanks Colu.  I don't have any Indian almond leaves on hand but will source some this weekend.  In the meantime, I added a low dosage of salt (1 tbsp / 4 gallons).  Will hold off on any meds and continue to monitor the water parameters.

[tuonor]

The Kubotai with a damaged fin was looking better initially but over the last couple days it has gotten worse and seems to have spread to a few of the other fish in quarantine.  Thinking this is now finrot?

First fish is the original one from the photos above...the second two are other fish that were acquired at the same time and had no fin issues previously.  Behavior is still relatively normal (schools and eats) but he is still pretty skinny.

These guys are still in a quarantine tank.  While water conditions were fine for the first week (small filter using cycled media), about 8 days ago we tested 0.25ppm ammonia and then a couple days later 0.25ppm nitrite.  Probably didn't have enough bacteria for the load of fish.

Since the first 0.25ppm ammonia result we've been doing daily 25% water changes and today (admittedly the first day we may have a handle on the water issue) both are testing zero.  Neither metric ever went above 0.25 (daily testing).  I did let the salt I added previously dilute down with the water changes which maybe was another mistake.

Other parameters are: pH 6.8, Nitrate 5, KH 4-5, GH 17.  Temp is 75.

Any thoughts on treatment?  I have kanaplex and kosher salt on hand as well as Ich-X and paracleanse.  Thanks again!

[Colu]

Am not seeing any Reddening to the edges of the fins o that would indicate an active infection is it possible there nipping each other what I would do is keep the salt at 1 table spoon for 3 gallons for a week and add some Indian almond leaves as they have antibacterial and antifungal properties you might have to add one leaf per gallon to get a beneficial effect if you start to notice the fins s rapidly recede or any redness to help fins or body then I would do a course of kanaplex 

[tuonor]

Unfortunately, this little guy passed.  His caudal fin eroded further and he stopped schooling with the other Kubotai.  We found him upside down at the bottom of the quarantine tank tonight.  This is what his fins looked like earlier today:

Could finrot have progressed this quickly?  Or is it likely he had another illness and that the fin issues were a secondary inflection?  Trying to figure out whether to treat the other fish.

Thanks for all the advice!

Edited 1 hour ago by tuonor