Quote Originally Posted by Photo Engineer View Post
Did you check the pH of the comparable PG containing developer?
Organics can sometimes change pH or distort their measurement.
Yes, using paper test-strips, I've been verifying a perfect color-match with unused XTOL. I'm using XTOL as an 8.2 buffer.
It's odd that 7% PG in a developer would have an obvious reduction in activity.
My last test boosted the PG from 3% to 7% with a noticeable drop in density. I wish I had a better understanding of the chemistry behind all this.

Quote Originally Posted by Ryuji View Post
Did you let the developer sit in a flask and see if there is any phase separation? (Like salad dressing made from oil and vinegar)
No, I tested the developer immediately after mixing, so neither concentrate nor working solution had a chance to settle. The working solution has now been sitting for hours, and a check a minute ago shows no separation.

I can only conclude that PG hinders development for some reason.

Mark Overton