I am attempting to standardize 4x5 film processing using stand development. I like my Jobo 3010 for evenness, but I like stand for tone. I am using a Yankee tank, developing 6 sheets of film at a time. I expose the film at ISO50 and use a dilution of 1:100 for N, N-1 is 1:200, N-2 is 1:400 etc. The tones are great but I am getting staining around the edges.

My agitation at first is rocking the tank side-to-side for 1 minute, waiting 30 sec and agitating for 30 sec. Then I develop with no more agitation for 1.5 hours.

Any ideas on how to get rid of the staining? Would a Combi-plan tank work better?