Wash the ingredients: Wash the 1 medium cucumber, sliced or diced, lemon, and any optional fresh ingredients thoroughly.
Slice the cucumber: Cut the cucumber into thin rounds or small pieces.
Add everything to a pitcher: Add the sliced cucumber, lemon juice (1 lemon, juiced), and any optional 5 fresh mint leaves (optional) or 1 celery stick, sliced (optional) to a large pitcher.
Pour in the water: Pour 4 cups water into the pitcher over the ingredients.
Let it infuse: Cover and refrigerate so the flavors can infuse into the water.
Serve chilled: Pour over 3 ice cubes, for serving and serve chilled. Add 0.3 teaspoons salt (optional) if desired.