You can use any type of unflavored carbonated water (sparkling water, club soda, soda water, or seltzer water), but I prefer to make my own sparkling water with a Soda Stream.
Pour the carbonated water into a pitcher. Add five scoops of stevia extra powder one scoop at a time (we use the scoop that comes with the stevia container). Be sure not to add all the stevia extract at once as the natural chemical reaction that occurs between the powder and the carbonated water will create quite a bit of bubbly foam! Stir the powder into the water to mix well.You can also add some stevia-sweetened flavored stevia drops (linked in the post) for additional flavor.
Add the lemon slices and the strawberries, then gently stir. Add ice if desired.