[pure-silver] Re: I say Ammonium you say Potassium
According to the CRC handbook, 42nd Ed., Nelson Gold oner (Kodak T-21) uses potassium persulfate in stock solution A. 4.0 L warm (125F) water, 960.0 g sodium thiosulfate, and 120.0 g potassium persulfate. Dissolve hypo completly before adding the posassium persulfate. Stir vigorously while adding the persulfate. If the bath does not turn milky, increase the temperature until it does. Cool and then add (including the precipitate) the following solution with rapid stirring. Cold water 64 mL, silver chloride 5.0 g, sodium chloride 5.0 g.
Ammonium and potassium persulfate should be interchangeable as long as you adjust the weights allowing for the different formula weights of ammonium persulfate and potassium persulfate. There is that old high school or freshman chemistry again. 


Howard
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