Ken:(posted 8462 days ago)Most film developers already have the appropriate amount of SS in the formula making it unnecessary to add any at time of use. Developers such as Microdol X or D76 that already contain large amounts of SS have nothing to gain by adding more to the working solution. However, developers like FG7 that contain only small amounts of SS can have it added to the working solution to shorten dev times and increase the solvent action. Some photogs also add small amounts of SS to Rodinal to soften the graininess a bit. Usually though, there isn't much to be gained by adding SS to an already formulated film developer.