Cause for concern?

[kribensis12]

So, I have a 29g hard water tank (we’re talking very hard).

I have a single Bolivian Ram, 5 angels (they are growing out - to be moved soon), 2 female guppies, 5 danios and (previously 5) black mollies.
Water Parameters:
Ammonia: 0
Nitrite: 0
Nitrate: 15 (missed a water change this past weekend due to family stuff - typically a 0-10)
pH: 8.4
Temp: 82 degrees

I do weekly 30% water changes and all fish seem to get along very well with one another - so I know aggression is not the issue:
My two oldest mollies (I would suspect 2 years old) have died within a week of eachother - they slowly lost their velvet black color over the past few months and began to swim erratically so I euthanized them.

The second one that died had a red patch on her gill plate (appeared today). My suspicion was originally old age but now… I’m not quite so sure. I’ve got a picture here to see what people’s thoughts are.

 

[AdoraBelle Dearheart]

Two isn't elderly for a molly.

But I'm not sure what it might be myself, so, @Colin_T

 

[Ch4rlie]

Red patches around gills is usually an indication of nitrite poisoning, also the colour losses on your mollies is another sign of nitrite issues.

Exposure to nitrite for long periods of time can make the fish immune system less effective and the fish may start to suffer from diseases like fin rot or ulcers and bacterial infections.

Did the mollies show any other signs apart from swimming erractically before you euthanised them?
Gasping, lethargic swimming, staying near top of water surface and perhaps holding fins nearer body than usual etc etc

 

[Ch4rlie]

Oh and can I also ask what type of water testing kit are you using?

 

[itiwhetu]

If your pH is 8.4 it is to high for freshwater fish. You need to find away to lower your pH.

 

[Ch4rlie]

If your pH is 8.4 it is to high for freshwater fish. You need to fine away to lower your pH.

Not necessarily as I had pH of 8.4 and TDS at 300+ppm in my last home location where I kept a number of tanks for years without too much issues, its just a case of finding out what was suitable for my water.

Also I found that due to the substrate, wood & IAL tannins etc did lower my pH of the tank gradually so the pH in the end was nearer 7.6 - 7.8.

Course its not ideal but there are ways to get around having hard as anything water parameters but I don't think 8.4 is too high to keep tropical fish, there definitely are certain species of fish and livestock that will cope fine with this provided water parameters are closely monitored and doing good weekly water changes and regular maintenances etc

 

[itiwhetu]

Be careful, there is difference with your fish coping and enjoying life. Just take care.

 

[CaptainBarnicles]

I don't think 8.4 is too high to keep tropical fish, there definitely are certain species of fish and livestock that will cope fine with this provided water parameters are closely monitored and doing good weekly water changes and regular maintenances etc

I agree, it's not always a problem if it's kept stable especially

 

[Ch4rlie]

Be careful, there is difference with your fish coping and enjoying life. Just take care.

Indeed this is something I concur with, a mantra that I sometimes say is that its always best to have fish that thrives rather than just survive.

Can be a fine line at times but with research and learning, there no reason why keepers cannot do this with very hard or very soft waters, just a case of finding out what works best for your particular tank and fish species.

 

[itiwhetu]

I'll do this once. pH is a logarithmic scale each 0.1 equals 10 times the previous value.
In this situation take the ram who wants to live in water at pH 6.8 and you are keeping it in water at pH 8.4. That is 16 points away from it's ideal situation or

1,000,000,000,000,000 times more Alkaline than where it wants to be.

 

[CaptainBarnicles]

I'll do this once. pH is a logarithmic scale each 0.1 equals 10 times the previous value.
In this situation take the ram who wants to live in water at pH 6.8 and you are keeping it in water at pH 8.4. That is 16 points away from it's ideal situation or

1,000,000,000,000,000 times more Alkaline than where it wants to be.

Not disagreeing with you here... but you generalised all freshwater fish, not all freshwater fish need a lower pH especially if its kept stable

 

[itiwhetu]

Not disagreeing with you here... but you generalised all freshwater fish, not all freshwater fish need a lower pH especially if its kept stable

Most freshwater tanks are best kept slightly acid than Alkaline. Exceptions are livebearers and African Cichlids. pH 8.4 is to high for any but the hardiest of the freshwater fish.

 

[kribensis12]

Red patches around gills is usually an indication of nitrite poisoning, also the colour losses on your mollies is another sign of nitrite issues.

Exposure to nitrite for long periods of time can make the fish immune system less effective and the fish may start to suffer from diseases like fin rot or ulcers and bacterial infections.

Did the mollies show any other signs apart from swimming erractically before you euthanised them?
Gasping, lethargic swimming, staying near top of water surface and perhaps holding fins nearer body than usual etc etc

I've never had Nitrite reading in this tank - it's always been zero (mature, established tank) and I feed sparingly. The other 3 mollies are much younger (fry from one of these, roughly 5 months old) and have 100% of their color. This tank has been disease free for over a year - no fin rot, ich, bacterial infections, bloat, popeye etc. No other fish in the aquarium has any discoloration on their gill plates or any other part of their body. These two mollies were swimming erratically, but not gasping. I'll take another Nitrite reading tonight for due diligence (and do their postponed water change/gravel vac)

Oh and can I also ask what type of water testing kit are you using?

API Liquid Master.

I'll do this once. pH is a logarithmic scale each 0.1 equals 10 times the previous value.
In this situation take the ram who wants to live in water at pH 6.8 and you are keeping it in water at pH 8.4. That is 16 points away from it's ideal situation or

1,000,000,000,000,000 times more Alkaline than where it wants to be.

I am aware. I do have several tanks that are pure R/O (remineralized) where I keep Apistogramma cacatouides and Dark Knight Microgeophagus ramirezi .The gH and kH are more important than pH of the water in my experience.

The issue here is that these rams are source from a breeder who bred and raised them at a similar pH and hardness level. This fish has only ever known these types of water conditions and I do not have tank capacity to place this singular ram in a tank more suited to it's natural habitat. The reality is that my cities water is extraordinarily hard and the likelihood that this ram would have had a much more poor existence in an unexperienced keeper's tank is extraordinarily high (but not a guarantee). If I had the ability to move this fish to it's own tank and acclimate it to water's that match it's natural habitat, I would.

I appreciate your concern for the well being of my fish - it is my concern too.

 

[Myraan]

I'll do this once. pH is a logarithmic scale each 0.1 equals 10 times the previous value.
In this situation take the ram who wants to live in water at pH 6.8 and you are keeping it in water at pH 8.4. That is 16 points away from it's ideal situation or

1,000,000,000,000,000 times more Alkaline than where it wants to be.

Isn't it each 1.0 is 10 times? Just checked wikipedia and the equation used for the scale is log-10; for what you are saying it would need to be log-100. I apologise for being petty though, as your point still stands, pH 8.5 is 100 times more alkaline than pH 6.5.

 

[Ichthys]

I'll do this once. pH is a logarithmic scale each 0.1 equals 10 times the previous value.
In this situation take the ram who wants to live in water at pH 6.8 and you are keeping it in water at pH 8.4. That is 16 points away from it's ideal situation or

1,000,000,000,000,000 times more Alkaline than where it wants to be.

pH 7.8 is ten times as alkaline as pH 6.8
ph 8.8 is ten times as alkaline as pH 7.8

So 8.8 is 100 times as alkaline as 6.8

82 degrees is very warm. The mollies might be ok but the rest will not be enjoying the heat. This will cause stress, which allows disease and other health issues. I’d drop it to about 78.