Start by adding the blueberries, strawberries, and one cup of water to a sauce pan. Bring to a simmer and cook for about 15 minutes.
If you have a stick blender use it, otherwise add the mixture to a blender, and blend for a few minutes.
Strain the mixture into a water pitcher, add the simple syrup, remaining six cups of water and a handful of ice. Place in the refrigerator for at least four hours before serving.
When you are ready to serve, add some ice to your glass and pour the blueberry agua fresca. Drink. Nothing beats the power of a simple, beautiful, and refreshing drink, and one that is perfect to serve for this upcoming Cinco de Mayo! Hope you enjoy.