Let me give a bit more history on washing.

Originally, texts suggested washing film in 5 - 6 changes of running water for about 30 mins to 1 hour. Prints on FB paper were about the same. In one case, it was due to the thickness of the emulsion layer, and in the other it was due to the DW FB paper requiring longer wash. I have alluded to this in previous posts.

Later, Kodak and others developed siphon print washers that used running water and a tray or tank siphon to change the total water in the container on a regular cycle of about 5 - 6 times / hour with normally running water. These recommendations are found in many Kodak publications in the 40s, 50s and 60s.

About that time, due to the concern over the environment, it was thought by some that still water with the same number of changes would give adequate washing. I discussed this with Bill Troop and he feels that much of the driving force came from England which had a water shortage in the 70s. Be that as it may, this practice was promulgated and began to be accepted.

With time, this 5 - 6 change of still water was repudiated by many as being unworkable. Well, the data seems all positive for running water, but variable for still water with agitation and changes. The equations by Mason show why. Buildup of waste products described by CBG in post 56 above enter into the picture as does the quality of the water and the operators expertise such as how well they drain prints and what kind of fixer do they use. It also depends on film and paper!

Therefore, the only "foolproof" method involves washing in running water. Any other method must be tested. In fact, I suggest tests be done with your condition no matter what you use. And, there are three ranges of wash, "normal", "archival" and "too much". Ctein has shown in his article on washing that if you overwash, you can cause problems with your prints just as much as underwashing. There must be just a tiny bit of residual materials left in the coating.

So, this matter is not simple and has no one answer. I say use what works for you, but test and don't overdo. Remember, hard water or film fix for prints can change your wash position totally, and FB prints on paper from one source may behave differently than FB prints from another paper source due to weight, baryta content and calendering.

PE