I use a Jobo ATL-2300 to process mostly 220 films. I use Kodak C-41B Developer Replenisher LORR to make C-41 developer by adding water and LORR developer starter. This developer so far works just like non LORR developer following Kodak's 3 minute 15 second development time. The Jobo ATL has chemical tanks of 1 liter in size. The processor is designed to use up to 1 liter max of chemical. So no matter how large my Jobo drum is and how many reels I can stuff in the drum I have only 1 liter max of developer to work on. I can easily load 1, 2, 4, 8 or more of 220 rolls in my largest Jobo drum, 15xx series of drums by the way. But I still have only 1 liter of everything for processing on each run. Obviously I can't process 8 rolls at a time, not even 4 rolls. I had hoped I could process 2 rolls at a time. According Kodak tech pub Z131 it takes 1 liter (possibly +/- a little bit) to developer a roll of 220 negative film. I have tried using 850 ml for one roll and the result seemed good. But I got an impression that people have reportedly saying it can be done with 500 ml only. My questions is what is the true capacity of Kodak C-41 developer? I believe Z-131 is a little too conservative so it probably takes less than 1 liter to process a 220 roll. But I doubt it would be 500 ml. It is likely somewhere in between. My next question is if 500 ml is not quite enough can I still do it by extending the processing time to longer than 3 minute and 15 second to compensate the capacity of the developer? It is easy for me to program my ATL-2300 to develop at a longer time. I don't really mind to use more chemical required to process my films. But I have only 1 liter to work with for each run. I would really like to increase my processing productivity to 2 rolls of 220 negatives for each run. How about mixing my C-41 developer at a lower dilution so that the developer is more potent? I hope I can get some answers or suggestions here. Thanks a lot folks.