I'm confused.

We're supposed to drink 50 gallons or so of water every day. But for some
reason, if we add anything to the water--like coffee or Crystal Light--well,
that doesn't count.

How come?

Black coffee doesn't have any carbs. Nor does Crystal Light (according to
the package). Specifically, why don't both of these drinks count towards our
water requirement?

Thanks.

Charley