Originally posted by abruzzi ... (though some films like Tmax need the fixer stronger to fully clear so you'll have to dump more often.)
You can also do what Kodak recommends for T-Max 100. A two-stage fixer step. That is, you fix normally with one mixed fixer and then fix with a second mixed bottle of fixer for an additional minute or so.
I keep a clipboard on the wall with the number of rolls I fix for both fixer 'A' and fixer 'B'. I mix a new batch on a fixed number of rolls of film processed per the directions on my fixer. Fixer B will last a much longer time than fixer A of course.
When advising someone to skip an acid stop bath and just use water, IMHO, you should clarify something about the process especially for a beginner. An acid stop bath is typically 30 seconds. That's too short for water only. A person new to developing might think that a single fill and agitating for 30 seconds is good for water only too. Stopping with water only really needs to be done by filling and draining the tank 5 or 6 times or so.