Quote Originally Posted by Ian Grant View Post

Concentrated Stock Solution.

Ilford PQ Developer (Conc) - Cool Tones

Phenidone . . . . . . . . . . . . . . . . . 1.25 g
Sodium Sulphite (anh) . . . . . . . . .125 g
Hydroquinone . . . . . . . . . . . . . . 30 g
Sodium Carbonate . . . . . . . . . . . .150 g
Potassium Bromide . . . . . . . . . . . 5 g
Water to . . . . . . . . . . . . . . . . . 1 litre

Use 1 + 9
Add additional Bromide or Benzotriazole to alter the tones to the working solution - as above.
Hi all, Just tried to mix this concetrated solution, but fell in trouble - first batch had crystals of Hydroquinone after 1 week of storage, then Idecided to make another batch with ethyleneglycol added to prevent hydroquinone crystallization, this batch gave worse result - everything crystallized in one large ice-like piece.....

Does anybody know how to prevent crystallization? Or maybe there is some mistake in the formula?