Quote Originally Posted by Sal Santamaura View Post
Anyone who's mixing XTOL stock using soft tap water of unknown iron content is asking for trouble. Mix XTOL stock using distilled (not "de-ionised," but "prepared using steam distillation") water. Store it in full glass bottles. Enjoy the benefits. See:
I used Xtol and soft and hard tap waters for many years, replenished, from it's release until about 5 years ago, never had a problem. The issue is iron content of the water.