I received a 4 liter bag of this fixer from Peters about a week ago with his request that I mix it, try it out and post my results on APUG. Here are my intial results.
This fixer is packaged as a mix of dry chemicals in a sealed bag. The net weight is 706 grams and the fixing agent is Sodium Thiosufate, together with another ingredient with an ammonium base, according to the information printed on the label.
I speculate that the ammonium compound is probably ammonium sulfate.
I mixed the dry ingredients in 3 liters of 100 degree F water (deionized 18 megaohm water from our continuously monitored filtration chain). The powder dissolved quickly and easily. I detected no ammonia odor. Cold deionized water was added to make a total volume of 4 liters. A very slight "sulfate" odor is detectable from the mixed fixer, but I do not find this odor objectionable.
At 70 degrees F, the newly mixed fixer had a pH of 7.01.
I measured the time required to clear a conventional (non-T grain) film. The film was 35mm efke KB 25 Emulsion number 310499, Expires 2006-9. At a fixer temperature of 70 degrees F 1 minute, 20 seconds was required to clear a 3 inch long piece of film. I repeated this test with the same result. I saw no visible remnant of antihalation die in the fixed and washed film.
Time permitting, I will test the clearing time for Kodak TMY 400 4x5 sheet film tomorrow.
I will also continue to monitor the fixer pH.