Very old rapid fixer

I have got 3 bottle of very old Fixer. It is the
Afga rapid fixer. However, there is large amount of white ppt at the bottom
of the bottle. May I know what it
is ? Can the fixer still be used ?

Ming.


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Ming wrote

I have got 3 bottle of very old Fixer. It is the
Afga rapid fixer. However, there is large amount of
white ppt at the bottom of the bottle. May I know what it
is ? Can the fixer still be used ?


That fixer is dead. Sulfur and perhaps some crystallized
ammonium thiosulfate are at the bottom of the bottles.
Sodium thiosulfate in it's dry form will last many years. The
ammonium form as usually made available for the darkroom has a
much shorter life span.
Those who are infrequently in the darkroom should consider
the sodium form. Used dilute it can be tossed after each use
with little wasted. That way it is always fresh, unused. Dan