Hard water effects: paint, clean, decals

[nickelplate759]

I recently moved to a place with very hard water. It's rented, so I can install a water treatment system.

Can someone share experience about what adjustments to make when finishing (paint & decals) models - I don't want white residue in my finish!

So far I'm using distilled water for decals.
I don't thin my paints with water anyway, but if I did I'd use distilled water there too.
To clean the model before painting - can I use tap water and detergent per usual, or should I try some other process?

Or - am I overthinking it and it's not really a problem?

[Ed Kapuscinski]

If you want to be safe you can always buy some jugs of the distilled stuff.

[nickelplate759]

I do.  The question is do I need to wash/rinse in distilled water?

[Wolf N Works]

Wash no
Rinse yes

Err on the side of caution. I have lived in areas with hard water and doing the above has never let me down.