About your ventilation, i am concerned your roommates might be offended by the smell.
It took me awhile to adjust my venting and fix all the leaks. Just be aware.
If i was you i would not get so caught up in making this a perfect run. Just record what you do and next time change only one thing. Go back and compare and make your own conclusions. Everybody’s situation is unique.
It is possible to have a high ph and low alkalinity. I am pretty sure someone in the eugene area has a meter to test your water for you. Start making friends and pick their brains.
You gotta make a decision and stick to it. If it is wrong then make a minor adjustment and try again until you get it right.
Killing a plant teaches you a lesson and keeping a plant alive gives you false sense of security.
They are comfortable with herb, that being said I am not trying to stink up the house too much. I have heard pretty good things about the filters for at least a grow or two, there is decent air moving out of the vent as well, but it like everything will indeed be a learning process. I think I decided to just drop the idea of messing too much with adjusting things, and just use stuff as they are, and see what happens. Maybe it turns out great, maybe it won't lesson learned perhaps. I just found worms in my pots when checking their moisture levels, made me quite happy as I had not seen them in there yet.