If your not sure about the sweetener,leave it out and use Lemon juice instead.
You can also use regular sugar.
I was told that I was diabetic last year and my Dr. asked if I used real or artificial sweeteners.
Then he told me that some artificial sweeteners are really bad for the body and are up to 4 times sweeter than sugar so it makes it harder to get off the stuff once your body adjusts to it.