I would recommend a sugar free electrolyte powder that you can add to water. Genius makes a good hydration formula available on Amazon. But also if you want a boost of energy with your electrolytes you can get something called ZipFizz.
I suffer from low potassium when I get sick or I fast. It causes the heart to pump harder and causes muscle fatigue. ZipFizz has a lot of vitamins and minerals including 20% of your daily allowance of potassium. That’s higher than any over the counter supplement. Those can be a much better deal if bought at Costco.
But I think something like the above might be your best option. And neither will knock you out of ketosis.
Drinking water mix with salt makes the water taste funny because of the diluted taste of the salt,I usually take a pinch/1 tsp of pink salt and directly consume it,it taste very salty to the tongue,but then I consume water afterward. It is much better than consuming water mixed with salt that taste not as fresh as freshwater and not salty enough due to the salt being diluted.Or instead of pink salt,you can go for salt that have been enriched with minerals and nutrient (it should contain Potassium,Sodium and most importantly Magnesium in which deficiency in this cause muscle spasm)
If you are doing OMAD (20-22 hours of fasting per day and then a meal), you can probably try making the “snake juice” recipe (in the “Electrolytes” article from the sticky post) at half strength. I find that half-strength is much, much more palatable. It tastes like just slightly soft tap water, not like salt water.
I only suggest half-strength because you should be getting some electrolytes from your OMAD, so you may not need the full amount as a supplement. If you made half-strength while doing extended fasting, you would need to drink twice as much to get the full amount of electrolytes.
PS: Electrolytes are what your body uses to send electrical signals in your muscles, heart, and brain. Without enough of them, your muscles, heart, and brain stop working as well — and if it gets really bad, they can stop working at all and you could die.
Science-wise, electrolytes are ions — atoms of sodium, potassium, magnesium, calcium that have lost or gained electrons, so they are charged particles. That’s how they can be used to carry electrical signals.
Of course, all of those things are minerals that occur naturally in the food you eat, so that’s where they usually come from. But when you fast, you aren’t getting them from food anymore — and you naturally pee them out every day — so you need to supplement.