If I fast from 8pm-12pm and wake up at 7am, for those 5 hours how much salt should I be adding to my water?
Electrolytes only become important when fasting for more than 3-5 days. What you’re doing is barely a fast… just a normal amount of time to go without eating. Your body has stores of electrolytes and will also re-absorb them from food in your colon.