I really like the Spindrift brand of sparkling water. It’s just water, and fruit juice, no sweetener. The lemon or lime are very refreshing, and it seems they recently added three flavors of lemonade to their lineup which I’m going to have to try now.
They are still a little sweet, and a liquid will go a long way to make them more in line with what you might want.
Anyways have a nice day!