Originally Posted by
joypulv
Don't assume copper corrosion because you see mineral stains.
Generally you don't replace copper unless it's really old or showing signs of going, such as all the valves and elbows leaking and full of deposits.
How old is your copper overall?
A water softener will help with mineral deposits in your water heater and in your fixtures, appliances, shower heads and faucets, toilets, and on your dishes, clothes, and skin.
As Tom said, you REALLY need to get your water tested before you start spending tons of money. There are water testing companies everywhere.