Someone suggested "elete" on this site a long time ago for electrolyte replenishment. It's got magnesium, sodium, potassium, and chloride. Just a few drops in a liter nalgene is all that's called for. It has no taste unless you overdo it. It works great in anything; juice, coffee, oatmeal, anything you can put drops on/in. I bought some to use when my daughter is exercising and for summertime when we're all generally hotter and sweatier anyway. I found it online somewhere.