In a 4-qt. freezer container, combine the water, sugar and limeade concentrate until sugar is dissolved; cover and freeze for about 48 hrs.
If I need to freeze it faster, I portion the mixture into smaller containers.
Plan for at least 24 hrs freezing.
Remove from freezer an hour before serving.
Chop mixture until slushy. Add sparkling beverage just before serving.
Garnish with lime slices if desired.
Notes
CAN I MAKE A SMALLER BATCH?
YES! I often will divide this up for smaller parties. It can easily be divided into 3rds. Use ¼ cup limeade concentrate, 1 cup sugar and 3.5 cups of water.