Tiger Barbs dying off, fast!

[Byron]

Well, the rapid respiration they have. The red gills/flared gill cover I don't think I see (although maybe it's just not obvious to my untrained eyes). And they are definitely not anywhere near the surface but rather sitting about as low as possible in the bottom of the tank. Thanks!

Their behaviour in the videos wold suggest to me that something toxic is in the water. I saw this the time I had a piece of grapewood that developed what turned out to be a toxic fungus/mold. I am not suggested that, just noting the symptoms would indicate something like this. When substances that affect the fish enter the water, the fish tend to swim away from it. Here they don't seem able to, suggesting the water is the same, whatever it is.

 

[utahfish]

I assumed that distilled water would not contain any chlorine or chloramine. I purchase Target store-brand distilled water which has an online purity statement that specifically states that it is free of chlorine. Thus I don't add conditioner to the distilled water, just the tap water. I don't know if this was a logical thought process or if it's a stupid beginner's mistake. Should I assume that what I'm seeing is chlorine poisoning? How should I proceed?

Couldnt hurt to use dechlorinator in the distilled water just to eliminate or confirm it as a possible culprit. If adding the dechlorinator improves the fish situation than its likely the distilled water was the problem if not back to the drawing board. Alsp chlorine and chloramine are different but both deadly to fish. Water treatmemts will add ammonia to chlorine to form chloramine so while the chlorine wont show up on a test the chloramine will show up in the form of ammonia, which could be leading to your mild spike in ammonia.
Id suggest when mixing water mixing the tap and distilled in a bucket and dechlorinating them together

 

[mark144]

Their behaviour in the videos wold suggest to me that something toxic is in the water. I saw this the time I had a piece of grapewood that developed what turned out to be a toxic fungus/mold. I am not suggested that, just noting the symptoms would indicate something like this. When substances that affect the fish enter the water, the fish tend to swim away from it. Here they don't seem able to, suggesting the water is the same, whatever it is.

If we assume that something toxic (i.e. fungus/mold) was introduced/developed in the tank, what would be my best course of action? If I remove the fish and put them into an uncycled tank, I would assume that would remove the exposure to the toxin, however I'm concerned about the potential shock caused by changing tanks, water differences, etc. If I did that, should I bring over water and/or filter from the current tank? Obviously that would not eliminate the toxin if it is in the water or in the filter, but it might reduce the continued exposure if it is in the substrate or in the plants. Would extra carbon in the filter help reduce/eliminate a toxic fungus or mold if I move the filter and fish to a new tank, leaving the substrate and plants behind?

 

[mark144]

Couldnt hurt to use dechlorinator in the distilled water just to eliminate or confirm it as a possible culprit. If adding the dechlorinator improves the fish situation than its likely the distilled water was the problem if not back to the drawing board. Alsp chlorine and chloramine are different but both deadly to fish. Water treatmemts will add ammonia to chlorine to form chloramine so while the chlorine wont show up on a test the chloramine will show up in the form of ammonia, which could be leading to your mild spike in ammonia.
Id suggest when mixing water mixing the tap and distilled in a bucket and dechlorinating them together

That sounds like good advice. I'll switch to doing my water changes that way from now on.

 

[JuiceBox52]

I would say to just do large water changes and try to identify the problem

 

[Byron]

We've no reason to assume a toxic fungus/mold, that was only my illustration of how fish react when a toxin is in the water. "Toxin" could be anything, Colin gave several examples.

If this were me, I would be doing massive water changes, using a conditioner. If their respiration improves, that means something is in the existing tank water; if they improve and then decline, that means something is coming from within the tank. I had this with a chunk of wood years ago...again, not saying that is what this is, only that water changes improving the fish which then deteriorate suggests a toxin leeching from something or somewhere within the tank.

 

[mark144]

Just an update. Two days ago in the evening, we lost three more. Leaving just one survivor. On Monday, when the other three died, he was looking just as bad as the others. Super rapid respiration, on the bottom of the tank, even resting on the substrate itself. Not eating nor moving. I've been doing 75% water changes every day since Sunday, being sure all water is conditioned. I also added a bubbler in hopes of oxygenating a bit better. I also dropped the temperature a degree because I read that

The tank was pretty heavily planted about a month ago, including three anubias petite nanas that were attached to driftwood when I bought them. I've been noticing that one of the three isn't looking great, some dying leaves and white fuzzy growth, as well as decay of the rhizome. After some more research, I believe what I'm seeing is what others are referring to as "rhizome rot" or "anubias melt". I found mixed opinions as to whether or not this would affect fish, but in an attempt to limit the potential source of toxins, I just pulled them out of the tank. I've done two aggressive gravel cleanings during water changes, being sure to eliminate any decaying plant matter in the substrate. I quarantined the sick anubias after treating it with H2O2. I'm watching it carefully as well as the other plants. I've also read about treating with potassium permanganate (Jungle Clear Water), diluted bleach, salt, etc. I'm not 100% sure what I'll do with them in the long term, but for now I'll keep them separated from the fish at least until I'm confident everything is back to normal.

As of this morning, the last one is still alive, and his condition seems to have improved markedly in the past two days. He's active, moving around the tank although still staying in the lower half. He seems distressed, though I'm not sure if it has to do with the water changes/tank re-scaping, some toxin still in the water, recovering from whatever it was that was killing him, or just the fact that he's now a loner when he's used to being part of a school. I'm concerned about the stress caused by having a social fish all by himself, but obviously I'm nowhere near feeling comfortable adding new fish to a potentially infected tank.

I'm not sure if we're out of the woods yet, but I'm starting to feel that he might actually pull through. I wanted to thank you all again for sharing your experience, excellent advice, and ideas on diagnosis/treatment.

 

[JuiceBox52]

@Colin_T

 

[Stan510]

If the water quality is even decent they should be doing well. Your fish might have internal parasites and are running rampant infecting all the fish. Fast breathing..obviousness enough, means something is affecting their gills.
I used Kordon rid ich when some petco fish infected all my fish in the 240 gallon.
There are so many drugs out there..I cant say Kordon is best. I'm not a fish pathologist.
You might go to youtube and look over the The Fish Doctors vids. It was one of his vids that got me on to the Kordon..the ingredient. It cured the large fish..but every mollie (6) died eventually. Those internal parasites are wicked on small fish,