You could say that it would be best.
In most cases, tap water isn't going be detrimental.
Ray has great advice- some of the best in the board.
I've actually taken to printing or writing down some of his comments.
What has really helped me immensely was just taking a couple hours a week and browsing his website before asking on here- most of the time, I found the answer to my question really quickly.
Here's his site-
First Rays' Free Info
And he just happens to have an excellent page on water supplies! Hopefully this will help you.
Water Supplies