Les's washing technic sounds interesting. I've not been aware of it at all. The conventional wisdom as i understood it was that one needed to leave the film washing until 12 full changes had occured....often 30 minutes or more. i've just cut to the chase and filled the tank (i use a daylight tank for 4x5 film just for washing after tray developing), sloshed the film, and emptied the tank 12 times. takes less than ten minutes and i've never had a problem. i like the idea of inversions though, however it won't work for my 4x5 negs.