8 cups water
zest and juice of 2 lemons
zest and juice of 2 oranges
1 Tablespoon epsom salts (drugstore food grade)
2 oz citric acid (drugstore or beer maker)
4-5 cups sugar

Boil ingredients for 10 minutes, stirring until sugar has dissolved.
Cool and bottle. Refrigerate.
Add 3 or 4 parts water or soda water to 1 part lemonade base.