Quote Originally Posted by Photo Engineer View Post
I have never felt that I had to use 2 "tank" fixing except in production situations. It is just too much hassle to me.
Hi, my main experience has been in production situations, but primarily color neg and print. From my considerable experience with effluent control, I can say that it would be extremely difficult for a lab to get silver in the effluent under, say 2/10 milligram/liter (not an unusual regulated number), without using multi-stage fixing. In fact, this is why "washless" mini-labs were introduced; low flow counter-current "rinses" were used, such that the total volume was small enough that one could afford to have a waste handler take it over.

If one is small enough that they are unregulated (or perhaps no one is looking at your effluent), and the chemical costs are insignificant, then it's probably not an issue.

And, BTW, for good prints HQ and Metol retention are things to consider. As you re-use fix, these build up in the fix and there is NO test for them. So, be careful.
I don't have any useful knowledge about the effect of these. Aside from what you (PE) say, about the only thing I'd have to go on would be Kodak literature describing a two-stage fixing system. In my mind, this is an endorsement of the system. (At least when Kodak sold B&W papers.) If one ignores any HQ/Metol retention issues, I would imagine that the same modeling methods I've successfully used for silver in color systems would be equally valid for B&W.