Recently I was getting uneven results while developing FP4 in Rodinal 1+100 1h with no agitation. It used to work well with old orwo film. I'm not sure what are the causes. I'm going to do semi stand this time - a few inversions at the beging and one or two at 30 minutes as from what I read it works even for other people. I have 4 or 5 rolls which I plan to develop. I used to develop one roll at a time as I had small tank. Now I have bigger one - 6 x120 or 5 x135. Is it safe to develop them at the same time with the agitation above? I'm bit afraid that higher tank can exaggerate problems with uneven development.