cave tetra disaster

Over the weekend I moved my cave tetras into my firemouth tank so I could start work on their old tank. The firemouth tank is 190L, a fairly mature setup, well filtered and stocked pretty low. However, within about 36 hours the tetras started looking awful; inflammation around the gills and the base of the fins, red blotches on their sides. As it stands, they're dropping like flies. I've never experienced any of my fish going from robust and healthy to fish zombie so quickly. Anyone got an explanation?
The parameters in their old and new tank are roughly similar, moderately hard, slightly alkaline. Ammonia and nitrites seem to be more or less nonexistent, nitrates are very low. In the firemouth tank are 7 small firemouths, 10 diamond tetras a small L066 and a Sturisoma aureus. Nothing else seems to be suffering. In fact, all other inhabitants are pictures of health. This was always intended to be a temporary home for them.
Btw, I initially worried it might be from bullying but of the cichlids only one exhibits any "attitude", usually just charging, and he spends far more time doing that to the other firemouths than the tetras.
Any ideas anyone?

Very sorry to hear this.
Normally, I would not expect a firemouth to bother too much with a blind cave fish.....and if the firemouths did, then you may only expect then odd fish to go down.

This does sound like a major systemic problem in the water as opposed to aggression from another fish.

There are a number of possible reasons, and I can only throw random guesses into the work without further info.
Usually, my first port of call would be a review of ammonia levels (poor health to fins and gills being the indicator there); the next would be nitrate levels (curled gills maybe.....darkening of the inside of the gills); and the next would be consideration of bioload (ie microbial load vs the tetras immune system). Parameters such as RedOx would be something that I would be majorly concerned with, but not all have access to RedOx test systems (ie was there a major change in RedOx ?)

Whilst it may seem like bolting the door after the horse has bolted, a major water change and addition ammonia adsorbing zeolites plus vitamin B1 supplements (in the form of AquaSafe or JBL water conditioner) is a minimun recommendation.

ian

igmillichip wrote:

Very sorry to hear this.
Normally, I would not expect a firemouth to bother too much with a blind cave fish.....and if the firemouths did, then you may only expect then odd fish to go down.

This does sound like a major systemic problem in the water as opposed to aggression from another fish.

There are a number of possible reasons, and I can only throw random guesses into the work without further info.
Usually, my first port of call would be a review of ammonia levels (poor health to fins and gills being the indicator there); the next would be nitrate levels (curled gills maybe.....darkening of the inside of the gills); and the next would be consideration of bioload (ie microbial load vs the tetras immune system). Parameters such as RedOx would be something that I would be majorly concerned with, but not all have access to RedOx test systems (ie was there a major change in RedOx ?)

Whilst it may seem like bolting the door after the horse has bolted, a major water change and addition ammonia adsorbing zeolites plus vitamin B1 supplements (in the form of AquaSafe or JBL water conditioner) is a minimun recommendation.

ian

Thanks for the info. I've just done some tests...

Ammonia... 0.25ppm
Nitrite... 0.00ppm
Nitrate... 10ppm

I haven't been able to find 1 of the bodies (it may already have been eaten) and I wondered would that account for the increase in ammonia?There are now only 3 left. All are blotch/inflammation free. None of the other tetras had curled gills, they were just very red, even by cave tetra standards. Would it have affected the cave tetras so catastrophically and yet left the others unharmed? The cichlids and diamond tetras look as good as they ever have and are showing no signs of distress. I did a water change a few days ago and did my usual thing of putting a turkey baster in the tank and squirting under and around rocks where I could, just so no crap builds up underneath them; there wasn't much. The sand bed is also pretty thin, thin enough that sometimes the base glass is visible in parts. I only mention this because I read that some of the things that can affect RedOx are faeces and mulm gathering.

I've noticed this evening as well, for the last few days all of the tetras were loitering in the bottom right corner of the tank. Not hiding, I think they were just gathering there because of a pleasing confluence of currents in the tank and less obstacles to avoid. The 3 left are now all around the tank and no longer sticking to one area.

Whatever this is, it's a new one for me. I've had fish ailing over time or getting bullied or just being plain suicidal but I've never had such a sudden and visible loss of health occur before. Either way, I have remedial work to do

The ammonia is worryingly high.
Search for a dead decaying body..................the ammonification part of the nitrogen cycle gets into action very very rapidly (and a lot faster than the process to remove ammonia).


There is a myth going around that RedOx is only of interest to marine keepers........what rubbish.

It is vastly more important to freshwater keepers than it is to marine keepers as a general rule.

Too often keepers make the big mistake of believing RedOx considerations are only associated with using Ozone. That is like saying you only need to worry about money if you shop in Harrods in a chauffeur driven Ferrari.

Another great piece of dodgyness is the saying I hear about "lowering or raising" RedOx......... meaningless really (although you can lower or raise RedOx buffering).

Methylene Blue is a bit of a wonder medication for many good reasons........there are some who call it an old-fashioned medication but what is old fashioned about a chemical that has brilliant medical use?

Anyway, one of the actions of Methylene Blue is that it is a RedOx reagent (and, thus, RedOx indicator). When people have added MB to a tank and said "it is stained dark blue for ages" that means that the MB is indicating the water is heavily oxidising............and that, in itself, could well be the indicator that the water is not suitable for some fish.

Yes, Mulm and bits will affect the RedOx potential.

As RedOx is all the driving force behind thermodynamic change, changes in the RedOx will affect how living organisms react to environment RedOx.

ian

I did a gentle move of the rocks this morning (boss firemouth wasn't happy!) and still no sign. I also did an ammonia test before I did a water change and it seems to have lowered slightly. Also, the 3 remaining cave tetras have rallied and resumed normal headlong sprinting around the tank. If the ammonia is lowering should I now see a spike in nitrites?

Where would I get a RedOx tester and are they expensive?

Re: Methylene blue... the wheel is "old-fashioned" technology. I'd still find it alot harder to drive to work without it . I used methylene blue from Sunday.

Thanks again for the information. Gotta love this hobby; it's a continuous learning curve.

At 0.25ppm, you may find the increase in nitrite is too low for the test kit to detect............even though the test kit may say it measures as low as that.
The nitrite would have also been converted fairly rapidly to nitrate if the tank is established anyway..............and 0.25 on a kit that can hardly measure anything below 10 and with a resolution not much better than 10 is not going to show an increase even if all that 0.25mg/l ammonia got converted to nitrate (it's like trying to measure the width a hair using the old garden measuring tape).

RedOx test meters are pricey enough, and even then there is not always a right and wrong answer as different natural waters have different readings anyway.

It is an interesting aspect of fish keeping that is too often ignored when diagnosing "unknown losses". But it is also somethign that need not be of major concern if good water changes are done and the tank is reasonably well cared for..............and you aren't adding potent oxidising agents (eg Ozone, concentrated strong acids) or reducing agents.

Methylene Blue is also an antidote for nitrate and nitrite poisoning (to an extent), I have also used it to overcome hydrogen sulphide and cyanide problems, it is used as an anti-cancer agent (photo activity) in certain cancers, it can protect the brain against a number of anti-cancer therapies......and a lot more including the basis of a number of human medications in brain behaviour.

Wonder-Drug.

ian

Did you acclimatise them to the new tank and surroundings ?

JustinK wrote:

Did you acclimatise them to the new tank and surroundings ?

I did but I think my mistake was putting too many in on the same day. I should have put them in in groups of 4 at a time over several days. I thought the filter could cope. The plus side, if there is one, is that I won't be making that mistake again.

JustinK wrote:

Did you acclimatise them to the new tank and surroundings ?

This is my first thoughts too. Most fish already carry some disease but can handle it once they are health, the stress of moving lowered their resistance and combined with the ammonia level in the new tank tipped them over the edge. Just goes to show how delicate a balance there excites in any tank.