Is it safe to dry fast daily 22:2? How much water to drink during the feeding period?
It depends what you eat. If you just eat juicy fruits you can probably not even drink any water (unless you sweat out a lot throughout the day, etc). If you eat heavy and/or dry food you should drink until you feel satisfied. I would start drinking 15 minutes before eating and then follow drinking 15 minutes after eating until you feel content. Your body will tell you when it is satisfied.
I do 30 hr dry fast then refeed. I start with ginger and honey in about 24oz of water as this helps my body to relax and also helps to restart the gallbladder. After my meal I drink about another 50oz within 3hrs ending with half a teaspoon of baking soda in it. Then restart my fast.