About distilled water

A question from a fellow grower:

Using Distilled or Reverse O water, there should be a ppm of around 0
and no pH. That being said, if you always use Distilled, what should you
aim for? In any event, what should you aim for? The ratio is 1 so a
DIF of 1?

The PH of distilled water is 5.6 to 7. Distilled water is a little acidic sometimes unless it’s distilled for med use the it’s neutral.