I can not keep close track. I'll do five 8x10s in a Jobo 3005, do two or three changes of water in the drum, then each neg goes into its own 8x10 tray. I fill and dump the trays a few times while I have a snack and get the next drum ready and start processing the next 5 negs. By the time the second set is done, I figure the first 5 are more than washed enough.