Quote Originally Posted by albada View Post
Ron, Then that's what I'll do. I picked up the pH meter today.

The formula I posted recently has a pH of 8.05. The test-strips said 7.8-7.9. You were right: They're significantly off.



With that encouragement, I decided to try removing the borate. The sulfite becomes the sole alkali, and I added ascorbic acid until the pH dropped to 8.0. Without the PG, here's the resulting simple 1-liter formula:

Sodium sulfite ................ 90 g
Phenidone ..................... 0.15 g
Ascorbic acid ................. 3.5 g
Target pH = 8.0. 7.5 min for TMY
That's it! And with a brief exam, I can't tell the difference between this formula and XTOL. I'm surprised. Has anyone before tried this simple PC-plus-sulfite formula?

Mark Overton
The formula type is new to APUG as far as I know.
But it is unbuffered, see posts #25 and #26 in this thread.
It may oxidize to the more acidic(I think) dehydroascorbate and fall in pH.
But one would have to do a long term comparative test with Xtol, both in contact with air,to see.