Quote Originally Posted by Rafal Lukawiecki View Post
Mark, thank you for working on this developer. I have been following your discoveries with great interest, as XTol 1+1 is the only film developer I use. I was wondering if you had any data, by now, about the keeping properties of the concentrate, since quite some time has passed since you begun.
Many thanks, and good luck.
Firstly: Alan: Thanks for doing the D-316 testing, and for the link about storage. I hadn't seen those postings.

Rafal, I have no results from long term tests yet. But I have some short term failures. For example, in one experiment, a concentration-ratio of 0.46 resulted in crystallization after a couple of weeks. I'm now testing a ratio of 0.40. The purpose of these ratio-experiments is to see how high concentration can be.

The concentrate (and sodium sulfite) will last longer if stored in the refrigerator or freezer. A few months ago, I put some concentrate in the freezer, and got no precipitation. If frozen, I would expect it to last for many years. Of course, you must remember to take the two bottles out of the freezer a few hours before you need them.

Mark Overton