I am missing the rant Mark. Please continue.
Yes ma'am.
Salt:
Here's another point of contention throughout the hobby which crops up regularly. To salt or not to salt?..and I'm referring to sodium chloride, not minerals intended to boost TDS for certain Rift Lake dwellers.
There is no need to use salt prophylactically in freshwater aquaria...period!
The lfs and big box stores regularly tell customers that "Aquarium Salt" is a necessary additive for the health of their fish. Just how much is needed is never exactly determined. The "Aquarium Salt" sold at the store is simply rock salt milled to a slightly smaller grain size. There is nothing special about it.
The reason that none of the store employees can tell you exactly how much is "necessary" is because the whole concept is made up to sell you something; and since it isn't a necessary additive to your freshwater tank, they can't tell you just how much to add.
The only fish which "need" salt are marine and brackish. Any fish which has evolved in fresh water doesn't need salt added.
Even otherwise knowledgeable aquarists fall into perpetuating this myth.
"It stimulates production of the slime coat." Yep...any irritant does. Fish secrete their slime coat as a natural process of living, just as forcing water past the gills is a natural function. They secrete extra slime whenever they feel an irritant or skin parasite. In a healthy, undiseased fish, stimulating the fish to produce more slime than necessary is needless.
"It prevents diseases." Really? Show me the proof.
Salt can be used in conjunction with elevated water temperature to kill the Ick parasite, but the continued immersion of the fish in elevated salinity won't prevent disease. In fact, salt can stress some fish to the point that they are weakened and thereby more susceptible to disease.
One of my favorite articles on this subject written by Robert T Ricketts, AKA RTR, can be found here:
http://theaquariumwiki.com/The_Salt_of_the_Earth
Mark