I'll repeat again that two bath fixing is better than one bath. BUT, two bath fixing is at its best and most useful in production work and not home use. For home use, it is very cumbersome. Also, I doubt if anyone here can easily measure Silver concentration in a fix in g/l! It is also very difficult.
Which brings up a very important point. A fixer with 1/2 g/l of Silver Chloride is less exhausted than one with 1/2 g/l of Silver Iodide! You see, halide matters and no one here has mentioned this so far. So, a fix exhausts faster when fixing film than with paper, and you run the risk of harming prints by having used a fix for film. So, in the final analysis the amount of retained silver IN THE FILM OR PAPER is the important factor here regardless of the amount of Silver in the fix. Kodak retained Silver solution gives a colored spot that can be measured against a published chart to determine the degree of fixing.
An example of this chart comes with most kits.
I must have been ludicrously over-washing prints all of my life. Residual hypo test came up clean today after a 15 minute wash...and that was without a wash aid. I was just running through some min time to max black and film speed test stuff....but got curious about the hypo and tested.
That was 15 minutes in a Zonve VI archival washer running at 1/2 gpm. The prints had been is a gently running water bath between the 2nd fix and the washer.
If you shorten the time, you may be surprised.
Remember that you can overwash.
I don't know if it's important that the stain darkened up to a borderline non-archival level when dry.
It's academic. It was just out of curiosity. I'll be testing washed prints that have had the benefit of toning and a wash aid, prior to the wash.
I think I'll pull and test from those at five minute intervals and use the first satisfactory time as my wash time going forward.