I live in oklahoma. I don't know of any metal ions in my water my concern is knowing the signs of its effects and preventing it. Someone mentioned a product by kordon . My fish is a 3" chocolate cichlid in a 75 gallon.
You could google your city name with "water quality report" after the name, and it should have a breakdown of everything tested. If there is nothing there, then why put the cart before the horse.