Why don't you try sugar free kool-aid. It tastes exactly the same without sugar. Might be worth trying...
Sugar is recommended to be little to none. Not easy to do though. Many flavored waters have sugar, or an artifical sweetner like splenda, equal etc. There are some flavored waters that just have a splash of lemon or lime but no sugar.
Kool-aid is just artificial flavorings plus the sugars you add. The water in that is pretty much overtaken by the sugars etc.