PLACE granulated sweetener and drink mix in large plastic or glass pitcher. Add water; stir until drink mix is dissolved.
STIR in juice cocktail. Use immediately or refrigerate until ready to serve.
POUR 3/4 cup of the prepared drink into each of eight tall glasses. Add 1/4 cup seltzer to each glass, then top with 1/4 cup of the ice cream. Serve immediately. Store leftover prepared drink in refrigerator.