I have a well here on the ranch so the water is hard to start with. For coffee or tea I filter it.

For one gallon of mix I add 2 tsp, or so to taste of Morton's lite salt (not their Salt Substitute that is pure KCL and difficult to find) 1/2 tsp baking soda, 1/2 tsp Epsom Salt (Magnesium Chloride) and 1/4 tsp of borax (20 Mule team)*
Used to add 5 drops of Lugol's the iodine may be good for you, but it tasted nasty

A glass of plain water with a Tbs or so of ACV (Bragg's is good) and helps with hydration. Also buttermilk, of all things works well in hot weather. And, of course there is salty bone broth preferred bones are from younger grass-fed animals.

*Health benefits of boron

https://www.organicfacts.net/health...rals/boron.html

https://www.lybrate.com/topic/borax...nd-side-effectsIt also puts lead in your Eberhard Faber

Humm ... this MiO thing looks interesting too:

http://www.makeitmio.com/en/about