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...

Quote Originally Posted by Ian Grant View Post
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...
Which is why I emphasized the unknown iron content of tap water, regardless of its hardness. Even if a single tap water sample is analyzed and iron found not to be a problem, variations throughout the year are inevitable.

Just like the decision to use less of a particular developer stock solution than its manufacturer's specified minimum quantity, this is a "confidence or crap shoot" situation.