Going off-topic but...(posted 8913 days ago)My experience with Ilfosol S (over many years) is that I always needed more development than recomended (for my enlarger setup), my personal EI for FP4 was about 80 and once the bottle was open it didn't last long! Once Ilfosol starts to change colour it's dead... Caught me out once, thankfully on nothing important!
I changed to Ilford Plus (LC29) and was much happier. I believe my EI is up around the stated 125, I develop for less than the recommended (pretty sure of this) and it keeps in an opened bottle much better.
However, after reading many nice comments about DD- X, I've bought some of that and are doing some tests. Too early to form any conclusions though (and I've been reading the PMK threads with interest!)