Actually to Mike (since you have this expired paper like me) and everyone. I am happy to report that I was able to get rid of the magenta cast. With repeatable results. Actually getting good black and white tones perhaps not as neutral as orthochromatic but within workable results to make the paper usable.

Please note that no matter what filtration I would use, I was always getting the same heavy deep magenta cast . So I never thought the filtration had to do with the problem as the magenta cast never changed. I am not an expert chemist in anyway so forgive if I don't know what actually solved the problem but here is what I did.

- I went and read the publication again g-4006 . this is the exert that lighted the bulb in my head.

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Processing conditions may affect the color (hue) ofPORTRA Black & White Paper. You may see a hue changeon the magenta/green axis due to variations in developer tankactivity and pH. Low developer activity and/or pH (typicallysevere oxidation and/or under-replenishment) will cause ashift toward a green hue. High developer activity and/or pH(usually over-replenishment) will cause a shift toward a
magenta hue.
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this is what I did as I figured this would lower developer activity... (I dont know how to check or modify pH)

- pre-wash 3 times until water came out fairly clear.
- I further diluted the developer by adding more distilled water to the working solution.
- I further diluted the stop bath , I figured this would reduce the acid.
- instead of using motor agitation, I did manual rotation (much slower) by hand .
- and what I believe to be most important; I lowered the developer temperature to 74F increasing the processing time from 45sec to 2 min.

voila, now every print comes out with no magenta cast, I mean none , zero. no color cast whatsoever. The interesting thing is that when the print would come out with the magenta cast, the stop bath would be dark bluish , but when prints come out without the cast, the stop bath would be pink. I wonder what happens in there....??