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 room temperature water in a small bowl until fully dissolved and smooth.
03 - Pour the spirulina mixture into the lemonade base. Stir until evenly colored throughout.
04 - Taste the lemonade and adjust sweetness or lemon juice as desired.
05 - Add ice cubes, lemon slices, and fresh mint leaves to the pitcher or individual serving glasses. Serve immediately while chilled.