Salt And Corys Etc

[KirkyArcher]

It's stated on many a thread in this forum that it's ill advised to add salt to aquariums or salt bath containing Corydoras, along with certain other species, what is the salt believed to/actually do to the fish that it's so frowned upon, mainly curious as my sister has regularly dosed salt in all her tanks after being suggested to do so by her father-in-law when she started the hobby and has a healthy shoal of peppered cory most of which are over 5 years old! 
 

 

[Fishmanic]

I'm glad you asked this question as I was going to ask the same thing.  I am setting up a new community tank and planned on getting a few corys.   I am planning on adding 35 tsp of sea salt to the 35 gallon tank which I believe is on the low side for salting a freshwater aquarium.   Would this amount hurt the corys?

 

[fluttermoth]

Some cories (bronze and peppereds are the two that spring to mind, but there are others) are more hardy than others and able to tolerate salt, but it's not good for them.
 
You shouldn't be adding salt to freshwater tanks. It used to be recommended in the 'old days' as it mitigates some of the effects of poorly cycled and poorly maintained tanks which were, unfortunately, the norm in those days.

 

[KirkyArcher]

 but it's not good for them.

 
Why is it not good for them, what damage does it physically cause?

 

[Blondielovesfish]

I may be wrong but I think it may burn them, almost like acid. 
Like I said, I may be wrong but that is my understanding of what it does to them.

 

[fm1978]

I believe it's a myth that salt can't be used in a freshwater tank with Corydoras.
 
Only some Catfish described as 'naked' are less tolerant of it but still shouldn't suffer any ill effects if the concentration of NaCl is correct to the volume of water.
 
As for the actual damage caused by salt to fish intolerant of it, I'm not entirely sure. At the least, I suppose, it would act as an irritant and induce stress and if that stress is sufficiently high, the immune system's ability to cope might be greatly reduced may leave them open to other infections, fungus, bacterial etc...  
 
At worst, if a fish, for example a naked variety of Catfish (I think Loaches are classed as 'naked'), was exposed to NaCl, it could enter the blood stream. I don't believe there's then a mechanism for fish to eradicate that salt and therefore, perhaps, leading the fish to be poisoned.
 
I don't know any of that for sure, I am just using some common sense reasoning! 

  I'd actually love to know if any of that is true!!!