01 - Combine cold water, lemon juice, and maple syrup in a large pitcher. Stir thoroughly until the syrup dissolves completely.
02 - Whisk blue spirulina powder with 1/2 cup room temperature water in a small bowl until fully dissolved and smooth.
03 - Pour the spirulina mixture into the lemonade base. Stir until the liquid achieves an even blue color throughout.
04 - Taste the lemonade and modify sweetness or acidity by adding more maple syrup or lemon juice as desired.
05 - Place ice cubes, lemon slices, and fresh mint leaves into the pitcher or individual serving glasses. Serve immediately while chilled.