Good to know. I suspected as much. It takes awhile for the brew light bulb to go off, sometimes!
I spent the last 6 months trying to understand my water profile (and why my beers [pale and amber] tasted so bad and bitter), now it got me thinking about the StarSan solution, too.
Why not the same problem?
If my water is really alkaline, wont't that "neutralize or buffer" the acidity of the StarSan solution and make it less effective?
This brew session is the first time I've used RO water (but, if I'm right, it's the best $1.50 I've spent [30 cents per gallon at the local grocery store] to make a batch of sanitizer).