not sure if this is what you want to hear b/c ur looking at carbonated water.. but i switched from bottled water to distilled last night and you can definitely taste the difference. yes i said taste. it' felt much cleaner and felt good once i had a couple glasses.
so in so many words... stick with distilled, add some salt for electrolytes. after 4/5 days the hunger isnt as bad, you dont need all that gas inside you to feel full.