It sounds as if you are exhausting back into the basement, if you are, you may want to setup a vent to exhaust outside. Moving my exhaust to a vent to blow it outside took care the smell issue with the rank girls I just harvested. If that is not an option, putting a new carbon filter on the end of your exhaust may help a bit until you can swap out the one in your tent. Another option, set up another carbon filter and fan combo free standing in the basement close to your tent to scrub the air.
Don't waste your money or time on ONA. It just adds a different odor to the mix. It does not neutralize the odor.