Peel the cucumber, cut it in half then use a spoon to remove or scrape off the seeds. Roughly chop the halves and place the pieces into the blender with the water, lime juice and sweetener if using. Blend until you have smooth drink without any bits of cucumber. Taste and if desired add more water or sugar or lime juice. Serve over ice cubes or place in the refrigerator until ready to serve.
Please notice that I don't add sugar or a sweetener to my agua fresca, but if you'd like you may do so -- it's all about personal taste. Additionally, you can mix in more water to thin down the drink, it is up to you. For a fun presentation, you can coat the rim of the glasses with some Tajin fruit seasoning or just ground chile powder.
White Cucumber Agua Fresca https://mexicanmademeatless.com/white-cucumber-agua-fresca/