GSD-10 + Fomapan 100@50 = lot of fog

Hello,
I tried to measure/calibrate the development times for Fomapan 100@50 with GSD-10 (21°C, stand-development).
Unfortunately I get a lot of fog. I measured a density of 0.235 on an unexposed spot after 20min development and a density of 0.320 after 40min stand-development.
This would result in 76min for normal development ... 76min seams to high for me.
Is GSD-10 not suitable for Fomapan 100 or should I use BZT?
Thank you for your advice.
Oliver

I think the high base density could be a result of prolonged developing time in stand development. You can try semi-stand or even regular agitation to reduce developing time if you are aiming for a lower base+fog rather than the compensation in full stand development.

Fomapan + "stand" development will give you a heavy base+fog density. Not recommended.