With PMK being so cheap - there is no reason to use the least ammount possible. I use the Jobo tank and fill it - 1.25 liters and do 6 sheets at a time and never have uneven development. I also belive that the accutance goes up when there is a 30 second pause between agitations that you don't benefit from when using rotary processing. I have used PMK with rotary processing - I bought the reccomended sequesturing agent and never used it and did not have a problem. I just think the results are better from the hand agitated tank - Frank