Keto Chow Electrolytes recommended by Dr Ken Berry in this and many other videos... https://www.youtube.com/watch?v=ThSHGUHPVj4

It barely changes the taste of the water, and a bottle lasts a very long time. I only use this as needed.

The guy on the front page who is 40 days in says he uses keto chow fasting drops.

https://www.amazon.com/Keto-Chow-Fasting-Drops-electrolytes/dp/B07DGKSF1P

Keto chow electrolyte fasting drops are extremely high quality and effective and gentle on the stomach. Electrolyte Drops