Wouldn't Sodium Carbonate raise the KH? of the tap at KH<1 GH<1 pH 9.0 to 9.4 (BTW i verified this with a chemist at the water department and was told they add Sodium Carbonate (not bicarbonate) _______________________________________________ Aquatic-Plants mailing list Aquatic-Plants at actwin_com http://www.actwin.com/mailman/listinfo/aquatic-plants