1. In a blender, process 1 cup of water, bananas and sugar until smooth. Pour into a large container; add the concentrates, pineapple juice and remaining water. Cover and freeze.
2. Remove from freezer 2 hours before serving. Just before serving, stir until slushy. Stir in soda. Serve immediately. Yield: 40-50 servings (about 11 quarts).