I sometimes have trouble drinking enough water when backpacking/hiking, so I flavor it with Nuun tabs, which contain good doses of electrolytes as well as vitamins (roughly 60% dv of vitamin c per tablet for example). This product will keep your salts balanced and flavor your water - seems like a much better solution. Also comes in a ton of flavors. I never experience cramping from dehydration since I started using Nuun tabs.
Also has zero sugar, less than one carb, and under 8 calories per tablet.
The tablets are packed in water-tight, durable tubes. I'm not a fan of sachets, as this creates more waste that you're going to have to pack out. The powder is also much more messy than a compacted tablet. The tubes can be reused for lots of purposes when you're done with one, I use it to transport waterproof matches, tinder, an emergency fishing kit, etc.
You can find it as running and cycling shops, as it is primarily used by endurance athletes. REI also carries it.