Quote Originally Posted by Photo Engineer View Post
If you run a keeping test of the dilute working solution, you will see how it performs with your tap water. By having a few volunteers run a similar test, we will learn a lot. PE
I'll need to do that. My intention is to make the dev last more than 45 minutes with hard water before it gets cloudy. It would be nice if it could sit around for a few hours or a day. The wikipedia article on citric acid here says it's an "excellent" chelating agent. But PE says there are much better choices around (Kodak likes DTPA). I guess we don't know if citric acid will chelate well in a developer, so as PE says, tests must be run. Also, I understand that the Fenton reaction with iron will eventually destroy the ascorbate, but that takes days or weeks, and this is a one-shot dev, so I don't care about Mr. Fenton. Although if I can chelate the iron for free, I will.

Rudi, thanks for the link to the list of stability constants. There's much useful data in there. I just looked up Glycine and decided it would be pretty weak.

Mark Overton