Don't get caught up in the numbers rigidly... if its 28 days then so be it... you didn't do it to fit a neat 30 days you did it for health. I broke at 29.5 days after hours of being convinced that I may not make it through the night if I don't break my fast. I cried at the thought of not going a full 30 days. I had such guilt/shame/remorse LOOOOLLLL but now I look at what a nutcase I was and how its just weirdo numbers that don't mean anything... What does mean something is the state of your health... If someone said "have you ever done a 30 days water fast" I would still say a big ol "yup".... and not hesitate.. anyone who says otherwise can tile the ocean and drink its water....
If you need to break - then break... salt in water, a few drops of lemon in a big cup... slowly slowly... break it for days days days for as long as you can and stay away from grains/carbs and other creepy things...
If you DO decide to have a coconut water for electrolytes to bring your heart health up the scratch dilute the daylights out of it like 1:5 parts water.