For a sweeter Coconut Lime Refresher, use 2 tablespoons of syrup per glass. For a lighter drink, start with 1 tablespoon of syrup and add extra sparkling water. Always add the sparkling water last to keep the drink fizzy. Store the coconut lime simple syrup in a covered jar in the refrigerator for up to 1 week. Assemble the drink just before serving for the freshest bubbles.