Might be a good idea to invest in a simple charcoal in line water filter
that will screw right into your hose.
It'll most certainly remove all of the hard water characteristics of
your water supply, and will be on hand when you need it, instead of
running for several gallons of distilled water when you need it.

Also a real good item to be using when washing your Van .
It'll prevent all the hard water spots.
And another idea for this item would be to filter your water on the way
into your Westies water tank.
I do.

The price?
About $28.00 including the charcoal cartridge.
A good investment.

RC