[Jordan]

Here's a formula that gives a developer with the same ascorbate and phenidone concentrations as MYTOL, has a similar sulfite concentration, and matches the pH of MYTOL's stock solution.

It should be simpler to mix in that it doesn't use sodium metabisulfite and replaces sodium ascorbate with the more readily obtainable ascorbic acid. You should be able to use it as you would use MYTOL or XTOL.

Start with 750 ml water
60 g sodium sulfite (anhydrous)
11.5 g ascorbic acid
0.15 g phenidone (easier to handle as a stock solution in alcohol or glycol)
13.4 ml triethanolamine OR 7 g sodium metaborate
Water to 1 L

Target pH of the stock solution is 8.2. Triethanolamine is a better buffer at this pH than borate, so the triethanolamine version is preferred. I'd appreciate comments on this formula.

Edit: This formula can be mixed as an organic solution as well. Combine 13.4 ml triethanolamine and about 20 ml of propylene glycol and heat in a water bath or on a hot plate. Add 11.5 g ascorbic acid and 0.15 g phenidone and stir until dissolved (it could take quite a while -- magnetic stirring will help -- addition of 1-2 ml of water may also aid dissolution). Then dilute with propylene glycol to a final volume of 50 ml. This organic solution should keep almost indefinitely. To use, dilute 1+19 with water containing 60 g/L sodium sulfite.