I don't have a 3d printer, but reading this thread has lead to to investigate 3d printing fumes. You really should not operate one without an exhaust hood or some really good ventilation.
Well, that filter looks pretty gunked up. Any chance that that is room dust? How much printing does that cover?
I like that filter housing from thingiverse. The problem I struggle with in the filter approach is: It helps but how to judge if it is good enough, especially some of the carbon filters.I'm still working on the vent as primary.