Geophagus dying

[squint]

Nitrate of 20-40 ppm may be too high for some Geo's, some species can be intolerant of such a high level.
Most of their natural water have nitrate under 5 ppm (if not 0), and the seasonal natural tannins, are also antibacterial.
If it were me, I'd increase my water change, and filter cleaning schedule to bring nitrate down to 10ppm or under.
And depending on how the breeder raised them, even 7.4 pH may be slightly high, depending on conductivity (mineral content), if the breeder used RO to bring conductivity down, and yours is high, it could be a problem.
You may wonder why only the Geo's are affected, and not the others.
P-bass seem to have a much higher tolerance for water with high mineral content, here in Panama they thrive in lake Gatun where pH often rises to 9 and the lake gets surges of sea water (although they don't get to the sizes found in the soft waters of the Amazon).

What are ammonia levels in natural waters? I bet it's way less than the 0.05 ppm that the API test can detect.

What about all the people who have 0.25 ppm per the API test?

If 2 ppm ammonia and 8,000 ppm nitrate are roughly equal in toxicity, 0.25 ppm ammonia is the same as 1,000 ppm nitrate.

We should be badgering people for 0.01 ppm ammonia as much as 40 ppm nitrate.

 

[duanes]

How Nitrate Levels Affect Aquarium Fish - The Spruce Petshttps://www.thesprucepets.com › ... › Freshwater Fish Health

 

[duanes]

What are ammonia levels in natural waters? I bet it's way less than the 0.05 ppm that the API test can detect.

What about all the people who have 0.25 ppm per the API test?

If 2 ppm ammonia and 8,000 ppm nitrate are roughly equal in toxicity, 0.25 ppm ammonia is the same as 1,000 ppm nitrate.

We should be badgering people for 0.01 ppm ammonia as much as 40 ppm nitrate.

One other thing, as a water chemist/microbiologist, I tested our source water from Lake Michigan daily for nitrate, when in the U.S. I never had a test exceed 1.0ppm.
And now that I live in Panama, whenever I receive fish, I check their natural water for nitrate with a API test, I have yet to see numbers above 1ppm.
And I went into the forest a while back, to check some natural pools during the dry season near where I live.
Water was shallow, due to to lack of rain, so I expected higher niitrate values.
Below was my result.


A study which I have misplaced, found that even moderate levels of nitrate in tanks seem to allow for a substrate to occur of fish gill membrane, which can be a pathway for for pathogenic bacteria to settle and infect.
I prefer to err on the low side for my tanks.

 

[squint]

How Nitrate Levels Affect Aquarium Fish - The Spruce Petshttps://www.thesprucepets.com › ... › Freshwater Fish Health

Nitrites, however, contain two atoms of nitrogen for each one atom of oxygen, while nitrates contain three nitrogen atoms for each atom of oxygen.

N2O and N3O?

Not surprisingly, there's not a single reference to a scientific paper to support her claims.

 

[squint]

One other thing, as a water chemist/microbiologist, I tested our source water from Lake Michigan daily for nitrate, when in the U.S. I never had a test exceed 1.0ppm.
And now that I live in Panama, whenever I receive fish, I check their natural water for nitrate with a API test, I have yet to see numbers above 1ppm.
And I went into the forest a while back, to check some natural pools during the dry season near where I live.
Water was shallow, due to to lack of rain, so I expected higher niitrate values.

What about ammonia levels?

We would probably need to use ion chromatography to measure levels low enough to match ammonia levels in the wild?

What about replicating stocking densities in the wild? Do we need 100,000 gallons per fish now?

 

[duanes]

My tests kit here in Panama showed a slight tinge of ammonia (less than the test would show as a number), so can't tell if was actual ammonia or simply noise from debris.
At the water facility where I worked, we used a spectrophotometer (forgot the brand, but it cost more than my truck), ammonia in Lake Michigan was usually around 0.02ppm during the heat summer, 0.00 in winter, on that device.

With the info given in the OPs post (although the problem could be anything from a latent disease just now appearing, to aggression), it was stated that water changes have been lax lately, and there is 20-40 ppm nitrate.
From that info was provided, to me, water changes are about the only reasonable, and non-harmful option.
The lack of obvious symptoms would not warrant any specific medication, the OP says no apparent aggression, but I do agree a quarantine/hospital tank would be useful.

 

[Matt101]

Sadly the weakest Geo has now died. The other one doesn’t seem to be worsening, but also not improving!

The other three appear unaffected. The other fish also appear completely fine.

Nitrates are now under 20 per water test last night.

 

[squint]

Maybe it's not nitrate?

 

[Matt101]

The other Geo seems to be continuing to get worse in terms of the marks on its body, mostly over its head.

is it worthwhile doing a salt dip?

 

[Matt101]

I’ve had a further look into this and it does appear to be Hole In The Head disease.

The Geo in question seems to have it very bad with another in very early stage of it (presume contagious?).

the other two Geos are completely fine.

what are the suggestions with the Geo that is now badly affected by it, albeit it does still seem fairly alert but not completely normal behaviour. Is the kindest approach to euthanise at this stage?