Here's an electrolyte drink made from real food and other ingredients ... perfect for the food sensitive. Drink it UP!
Finely grate ginger and, using a flexible spatula, press solids into a fine-mesh sieve set over a small bowl; discard pulp. You should have about 1 tsp. ginger juice.
Combine ginger juice, lemon, lime juice, sweetener, and salt in a large measuring cup or pitcher. Stir in mineral water. Pour over two glasses filled with ice.
You can make the lemon-ginger mixture one day ahead. Cover and chill. Then stir vigorously before adding mineral water.