Zest the lemons. Juice the lemons.
In a pot over medium heat, add sugar, lemon zest, and two cups of water.
Simmer stirring occasionally for about 5 minutes or until the sugar has dissolved and the mixture has a yellow hue. There's no need to boil the water.
Strain the lemon juice and sugar mixture into a 2-quart pitcher to remove the pulp, seeds, and zest.
Add in 4 cups of water.
Taste for sweetness and if it's too sweet add more water.
Pour some into ice cube trays and refrigerate the rest.