01 - Combine cold water, lemon juice, and maple syrup in a large pitcher. Stir thoroughly until syrup dissolves completely.
02 - Whisk blue spirulina powder with room temperature water in a small bowl until fully dissolved and smooth.
03 - Pour spirulina mixture into lemonade base. Stir until color distributes evenly throughout.
04 - Taste lemonade and adjust sweetness or acidity with additional syrup or lemon juice as preferred.
05 - Place ice cubes, lemon slices, and fresh mint leaves into pitcher or individual serving glasses.
06 - Serve immediately while chilled for best flavor and presentation.