Juice lemons with lemon juicer. Set aside.
In a pot over medium heat, warm the 2 cups of water and 2 cups of sugar, stirring occasionally. It is done with the sugar is completely dissolved.
Let cool.
Mix together in jar or jug the lemon juice, 12 cups of water, and sugar syrup.
Slice up extra lemons and place in the lemonade for garnish.
Store in fridge until ready to serve.