My father is the source of 99.9% of my photographic knowledge. He's full of useful information and wisdom! Recently he shared this tidbit about removing water spots from negatives, and since I know this is a problem for me occasionally, I thought I would share it here. (Note the extra little bit of wisdom about what chemicals *not* to mix together)
Removing water spots from negatives
by James Jasek
Occasionally water marks will form on negatives after they are dried. These spots can be removed by using the same bleaching bath used in toning. This is followed by a brief wash in water, then redeveloped, for the usual time, in any developer, washed and dried.
Water 32 parts
Potassium Ferricyanide 1 part
Potassium Bromide 1 part
This can be 32 millimeters of water to 1 gram Potassium Ferricyanide, and 1 gram of Potassium Bromide.
Small quantities of photography chemicals can be purchased from:
A word of caution. Do not mix Potassium Ferricyanide with any acid as the acid will cause Cyanide Gas to form and this gas is deadly. One whiff and you can end up dead on the dark room floor.
Another simpler method is to soak the negative in any developer such as Dektol to soften the emulsion then wash. Fix to harden the emulsion and wash and dry. Add a few drops of Photo Flo to the wash water. Then squeegee the negative with a clean cotton pad and hang up to dry. Using Photo Flo and removing excess water from the negative will prevent water spots from forming on the dry negatives.