I am nearly 20 years post op and never drink electrolyte solutions (mostly because I dislike them). I drink when thirsty and if feeling tired or "off." The only time I have had serious dehydration issues is when I have been ill. But, I do not do extreme workouts or spend long periods working in the heat, etc.. I do not limit my salt intake either.
My personal guideline has always been the color of my urine. If it is too yellow, I need more fluids. Muscle aches and headaches can be a sign of dehydration.
Jan