Drinking Water Additive

[PurplePoodle]

Just curious if any of y'all have tried any drinking water additives in your camelbak or canteens? I know that even if I drink a ton of water I sometimes still get major leg cramps after a good wildland fire. Alot of times I feel a ton better after drinking something like gatorade or something with some electrolytes, but I don't want to put gatorade in my camelbak because sometimes it will sit for days or even a week before it will get drank and I don't want it to go south on me. I was hoping that you might know of something that comes in individual packets so I can leave plain water in my gear and then just add when I need it??
Thanks,
Poodle