My New Guppys

[OldMan47]

I am sorry to need to disagree with you HelterSkelter. Although some small nitrite tolerance can be shown for very low level salt additions, it is not a tonic although that misconception is widely circulated. I am sure you have seen it in many places but that simply does not make it true. The truth is simple, no fish thrives in water that is not suitable to the particular fish although many can survive well outside their natural water preferences. Many of the common livebearers come from water that is relatively high in mineral content and will thrive in water that is also high in mineral content. For people that have tap water more suitable to tetras, salt can increase the mineral content to a value suitable for our common livebearers, but that does not make that water ideal for them. On the contrary, that water is slightly brackish in terms of salinity but does not have the right blend of minerals to truly suit the fish. It is a quick cure that will kill off your plants and leave the fish in less than ideal conditions.
Sorry about the rant but this is one of my few hot button subjects. If you start supporting salt for fresh water, I am almost guaranteed to step in with a comment.

 

[helterskelter]

Ok breath again OM47.

I to do not support the use of salt either, never have done. At a treatment yes.

All I'm saying is that, salt dose help reduce the work load internal organs esp the kidney (may be liver cant remember off the top of my head though).
This is what shop's play on, when advising this. The fish may live a little bit longer but in my eye that longer exposure from any toxins in the water.
Like you say, you try this with soft water fish in general, they will not tolerate it.

Sorry for not explaining this fully over half a page. Perhaps I dont spend enough time here and should be more in-depth!

 

[OldMan47]

Salt does indeed increase the mineral content of water which might possibly benefit a small and restricted group of fish in certain very narrow water situations. What you are saying is that the particular fish need a higher mineral content than they would otherwise have and the salt has provided them with a small increment of benefit. I cannot dispute that as it is entirely true. The problem we see is that people will think that what benefits one of the fish they have in their tank will also be a tonic for the rest. Nothing could be farther from the truth. Fish control the mineral content of their bodies by either constantly urinating, as we see in most fresh water fish, or swallowing water as we see in many brackish and salt water fish. What the fish's natural reaction to mineral content may be depends more on the particular fish than on the water they find themselves in. If a fish is naturally wired up to shed lots of water while retaining minerals, we will likely call it a fresh water fish. If it is naturally wired to shed tons of salts and other minerals while retaining lots of water, we probably consider it a saltwater fish. If you happen to have a fish that is slightly off balance in a range that adding a bit of salt will help their natural method of balancing salt content of the water, they will benefit from a small addition of salt. Otherwise, the addition of salt to an otherwise freshwater tank is not a tonic or a benefit to the fish. It is one more thing the fish's natural coping method must deal with, another unnecessary burden to the fish's adaptive abilities.