Just thought of something, in relation to my own process as well as to the question of Miguel's odd batch of film. I assume old fixer (ie, used multiple times) takes longer to clear/fix than freshly mixed fixer? I'm assuming this because there would be fewer molecules of oxidized (reduced? this always confused me in chemistry class as well) fixer to interact with the silver in the emulsion. My question is, HOW much longer? Assuming the "old" fixer still passes a hypocheck, do I need to add fixing time as the fixer sees more uses? Maybe I should go back to 6 minutes to be safe ...