Oh a pure water fast, no. We have a girl on here that did a 21 day fast with water/tea/coffee and propel. She was in my fasting and actuallyMade it - I have a really tough time with electrolytes and I had to end at day 8.
Go for it! I’m about to start a 5 day myself ♥️
You can “do” what ever you want, of course. But why you ever want to drink that is purely a matter of opinion. Drinking anything with artificial anything during a “fast” seems counter to the very concept of a fast, but you can eat ice cream and call it an “ice cream fast.” No laws - just judgment.