In medium saucepan, combine sugar and 2 cups of the water; mix well. Bring to a boil. Boil 3 minutes. Set aside to cool slightly.
In large nonmetal freezer container, combine concentrates, remaining 3 cups water, the schnapps and lemon juice; blend well. Stir in sugar mixture. Cover; freeze at least 8 hours or overnight until frozen, stirring 2 or 3 times after 2 hours.
To serve, spoon 1/2 cup slush mixture into each glass. Add about 1/3 cup ginger ale to each; stir gently.