looks like your hard water can cause even further damage:
"Hard water causes two problems:
It can cause "scale" to form on the inside of pipes, water heaters, tea
kettles and so on. The calcium and magnesium precipitate out of the
water and stick to things. The scale doesn't conduct heat well and it
also reduces the flow through pipes. Eventually, pipes can become
completely clogged. "
from:
http://home.howstuffworks.com/question99.htm