My husband a type 1 Diabetic drinks Smart Water. It can be tough to find, I know that Kroger and Trader Joes has it. He uses this water and adds the Crystal Light single packets to it.
Also, in a book, entitled The Diabetes Solution written by Richard Berstein, MD (also a type 1 diabetic), there is a recipe for making a water solution that replaces electrolytes.
And wow electrolyte replacement is soooooo important. Last May my husband was helping my father roof his house and he was drinking lots of water, but not replacing electrolytes. He ended up in hospital special care with DKA.
He has a pump, but since he was essentially dehydrated none of the insulin was being absorbed, so even though he was increasing his dosage his body wasn't getting the insulin. Had to get insulin from IV.