Ian, in this formula

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

Sodium Carbonate mono or anhd?

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