I use spring water. You can buy gallons of it at Walmart for pretty cheap. But I give mine showers in the Shower and thats Tap water of course. I mainley use spring water for the life of the misting systems.
But its up to you
And thats right everyones tap is different.
Thanks for the responses, it sounds like I can use tap to distilled, that it is if my tap water is good, I live in California, and I do filter my tap water already.
If your tap water is high in chlorine and/or fluoride your can put it in a glass with a paper towel over it for 1 to 2 days and most of the chemicals will disperse out of the glass. If you use a Brita filter (or like device) it does pretty much the same thing (just with a different method).
This is the method I used when I lived in the city. Most water you see marked as bottled spring water is still treated with chlorine.