Pop wrote:
So, best case, you might be able to figure it out yourself by
tracing your pipes. Also, water softeners aren't using table
salt as you are thinking: It's a different type of "salt"; look
at your bags for contents, and you can discuss that with your
doctor if it's an issue.

It's salt: Sodium Chloride. Water softner salt and table salt differ in
purity but the main ingredient is chemically identical.

Worst case, there are testing laboratories in the yellow pages
that can test your water for about naything you can think of; for
a price.

Luck!

Pop