This is a fun drink kids can make as well as adults who want to control sugar intake. Compromise.
take a can of seltzer, and pour over ice in a tall glass.
in a separate glass put a scoop of lemonade mix (or any flavor mix for that matter) and a few tablespoons of water to form a hi concentrated liquid.
mix the concentrated syrup with the seltzer a bit at a time until flavored to your liking for your family.
the only thing this does not work well with is iced tea. we have used Kool-Aid, and even store brand flavored juice mixes which work best. I also recommend always diluting with water before adding to seltzer. my sons friends love this too.