I have been facing this problem for quite some time. I can't seem to figure out why this is happening. Any suggestions? It seems random and the pattern is always the same. Below are two scans of two separate negatives developed on two separate runs showing the problem. I have increased the contrast in PS to make the problem more evident.




Things I have tried to eliminate this

-Levelled the drum on the rotary base making sure there is no wobble as it spins
-Used fresh stocks of Xtol
-Pured dev on opposite compartments of the jobo 3010 in reference to film
-increased frequency of changes in drum development spin direction

My dev is
(done on cibachrome motor base)

5-10 min prewash (multiple water changes [~2-3])/ flip direction per wash
4 min dev /flip direction every 30s
1 min wash with water /flip direction every 30s
6 min Tetanol super fix plus /flip direction every 3min
1 min wash with water /flip direction every 30s
3x 5 min wash with water /flip direction per water changes
take negs out of drum and immerse in water+tetanol mirasol
dry on clothesline initially "mopping" away the excess buildup of water at bottom edge