Freshwater fish are called freshwater for a reason. Just because your LFS or your buddy does something to his tanks, doesnt mean its a good idea. Will keeping salt in your tank be harmful to your fish? Probably, eventually. You wont see a difference immediatly, or maybe even in a year. But chances are they wont live as long as they would have otherwise. No, I dont have any "evidence" to link to. But I'll look, although pretty much everything on the internet is just someones opinion.... :read: