jdef makes a good point: What alkali bath (if any) are you using?

Phenidone and Ascorbic Acid will dissolve in ethylene glycol (with continuous stirring) at fairly low temperatures - in the range of 70F to 150F. When I mix with any of the glycols, I start mixing at room temperature and add heat only if needed - and then only enough to get the chemical(s) into solution.

Hope that Pat Gainer will contribute from his experience with these developers.