i do not want to be critical of anyone, especially someone who is fasting, as to many Christians do not fast, or or do not fast enough. So I certainly respect any Christian, fasting, whatever the fast is (within reasonable boundaries of course). I also will add that I do not know the specific objectives of why Grace777 fasted on green tea.
Still, and here comes the "but" - (sorry)...but as a general rule, I certainly do not suggest anyone fast using green tea. It has enough caffeine in it to essentially negate many of the good things a fast does to clean up the body.
The chemical compound caffeine also negates some of the spiritual benefits of the fast.