Your fix routine is a mix of contradictions & errors.
Originally Posted by Richard Jepsen
First: it is a paper no one has ever encountered which
takes 4-6 minutes in film strength rapid fix. Especially
the way your fixer is being used.
Second: TF-4 needs no HCA treatment. So, the 10 of the
Ilford 5-10-5 sequence is a waste as such. It might count
as wash time.
Third: Once you've strayed from ONE minute you've
strayed from Ilford's 5-10-5 sequence. When Ilford
in the early 80s announced the sequence the time
in fix was 30 seconds; later 60 seconds. Large
prints need the extra for a more even fix.
Forth: I've not mentioned the word Archival. Ilford
no longer espouses such a fix routine; no longer has
an Archival anything. IIRC the phrase now is Optimal
Permanence. The OP routine centers about remaining
within a fixer of very low silver levels. They highly
recommend the two bath fixer.
Approximately 3/4 of your TF-4 fixer is going down the
drain unused. Even Ilford's now gone Archival Processing
Sequence allowed for 40 8x10s per liter of film strength
THEIR fixer. That is no longer the case. Ten prints is it
if the OP low silver levels are to be met. The way to
greater capacity? Put 40 through the first and
second bath of a two bath fix. Dan
The last poster is correct concerning the low number of prints per L to reduce fix silver content. I've reviewed the literature many times before I settled on my fix process.
The rest of my process is to lightly tone in KRST and extend the final tray wash to 25 to 30 min with no less than 6 to 7 fill and dumps. I've been confident of my processing since it is conservative.
I have a small dry darkroom and use the 1 min fix routine sacrificing economy for convenience. Theoretically my process should have OP with typical papers. But, EMAKS instructions recommends a 4-6 min fix time. I have no idea why their time is different from Ilford/Agfa/Forte. I made the post to receive feedback on the best course of action.
Most likely the processing instructions are for paper strength vs film strength ratios. The manufacturer provided minimal instructions. Liquid-concentrate fixers are normally faster than a powder derived fix.