Peel the skins off the lemons and limes and wash the berries and mint stems. Add 2 cups of berries with the lemons and limes and pinch of stevia to the blender with just 1 cup of the water to get it going. Blend extremely well until the berries are very well blended. Add remaining filtered water and blend well, adding stevia to taste. It should be a bit sweet because you have yet to dilute it with the mineral water. Pour over packaged ice cubes (they don't melt in your drink) or frozen cranberries and mint sprigs into a nice carafe/ jug. Add sparkling water and stir. Add any sweetness needed to taste. Enjoy!