Fantastic, thank you so much for the response.
So in short, best bet is a 6" fan and a carbon filter of around 50cm.
Should I be concerned with the m3/h of the filter vs the fan?
Then, I've been looking at the HIT150 fans, I see they have 3 different speeds one can wire for. How would I know at what speed to run it for the filter being used?
Sorry for all the questions, I just started out with this and wow everything is adding up very quickly price wise . I am also trying to learn as much as possible and realize that I might be over complicating some aspects.
Thanks a gain for the help.