Halve the melon and remove the stones with a teaspoon and place in a tall container (use the pulp for other purposes!). Add the sugar and 1 liter of cold water. Mix well with a hand blender or in a blender until all of the kernels are shredded. Let this mixture steep in the refrigerator for about 3 hours.
Stir briefly and pass through a fine-meshed sieve. Serve chilled. As a small variation, it is also very tasty with a little vanilla, cinnamon or lemon juice.
The amount of sugar is of course a matter of taste, you can take more or less. In addition, all or part of the sugar can be replaced by sweeteners.