So I finally got around to running my highly unscientific test to see how long NACL plus citric acid powder would keep your water and glass unfouled. I didn't measure, and I didn't add anything other than my customary 1 drop of lemon balm for taste. One week plus later, I finally dumped it, more for the specks of herb floating then general grossness. The water got slightly cloudier as the week progressed, but never lost the pink color. For kicks, I used my dual chambered beaker style that works great with a Solo, and used distilled water for the bottom and tap for the top. No difference whatsoever in color changes and such, and when I washed it with some dishwashing detergent, it sparkled from top to bottom. No hard water line either. For those of you that distilled water isn't readily available for, I've had this powder for years and only a little sprinkle does the trick. The only thing I'd caution is that your water's gonna be super puckery (all the lemons, all at once!) so if you have glass that tends to splashback, plan accordingly with levels and all that.