Combine the blueberries with 4 cups of water and blend them in a food processor or blender until smooth and homogenous.
Pour the blueberry mixture into a large pitcher and add the lemon juice, sugar, and remaining water. Stir the mixture until the sugar has fully dissolved.
Serve immediately and enjoy!
Notes
If you do not have fresh blueberries, use frozen ones that have been thawed in the fridge. You do not want them to be frozen when you blend them.This lemonade will be good in the fridge for about 6 days. You can also pour this lemonade into a popsicle mold for a yummy frozen treat.