In 2 quart bowl, add 1 cup water and microwave for 1 minute. Add sugar and stir to dissolve. Add lemon juice and grated peel. Stir. For 1 serving, mix 1/4 cup syrup and 3/4 cups water in glass. Add ice. For 1/2 gallon, add 2-2/3 cups syrup and 5 cups water. Stir.