Pushing Delta 100 with Redfilter

[JayJayOkocha]

I shot a roll of Delta 100 with a BW091 Redfilter. To compensate for the 3 stops extra that this filter needs, I shot at ASA 12 to ASA 25.
I now want to push+2 develop that roll in Kodak D76, diluted 1+1.

Can somebody help me out with the correct developing time?
Do I develop the film at ASA 12/25 (4.5/7min) or at ASA 400 (14.5min)? I am trying to wrap my head around it, but because of the involved redfilter everything is a little bit more complicated.

Thanks a lot for your help!

[Ari]

You already compensated for the filter by opening 3 stops.
I don't think you need to adjust your processing. Develop normally, 100 ASA time.

[JayJayOkocha]

Yes I did compensate for the filter but I want to increase grain and contrast, thats why I thought about pushing two stops

[Peter De Smidt]

The best way to figure this out is to do your own tests. If you don't know what your particular exposure/development system will lead to, then you're just rolling dice. If the roll has important pictures, then shoot a different test roll using the filter and under similar lighting conditions. Then develop the test roll and evaluate. Development times depend on exact temps and agitation schemes, along with exposure and desired results. What other people recommend can at best be a rough guide.

[koraks]

A ballpark/seat of the pants compensation would be to add something like 30% to the normal development time. This will give a significant boost to contrast. From there you can adjust to taste for subsequent rolls.