Fixing two different film brands together and different result

[Zach-MLT-MD]

I've never been advised against mixing two films from different manufacturers in the same developing tank. As long as the process times are similar for whatever chemicals and method you use, it ought not to be a problem. I have certainly been known to process rolls of Foma along with Kodak or Ilford.

I just had my first pink/meganta HP5+ yesterday. It's from the middle of a bulk roll, fresh and in date. The only thing I have done differently to my usual procedure is that I used Tetenal Superfix rather than my more usual Ilford Rapid Fix (I've also had good results with Adofix). The pink hue disappeared almost completely in the final wash, with the wash water being visibly light pink.

I mix and match ilford kodak and foma all the time - as long as the develop times in my DDX are teh same for whatever speeds I want to develop it works fine as far as i can tell. I too get pink stained wash water though ive found more so when im processing trix.

 

[37th Exposure]

I do a clearing time test before processing. I find that HP5 Plus always takes longer to clear than Foma 400 therefore HP5 needs more time in the fixer. Try it for yourself with your fixer. The Golden Rule of fixing has always been "fix for twice the time it takes the film to clear" though some respected sources such as the Ilford Manual of Monochrome Darkroom Practice (Coote) or The Darkroom Cookbook ( Anchell and Troop) suggest fixing for triple the clearing time.

 

[LAG]

...fixing for triple the clearing time.

That's the way I do!