Don't know if this is practical for you, might be a bitch to unmount things. But if you put all your plants in one room and sorta seal that room (doesn't have to be airtight at the molecular level ) you could assemble just the fan / filter combo and run it as an internal recirculating scrubber --not venting it to outside the grow area, if that makes sense. Just the fan pulling stinky room air through the filter continually, and recirculating it within the room.

Now, you can't keep this up forever; you'll need to eventually vent some fresh air (CO2) into the room, and vent out the heat produced by the fan motor. But this shouldn't take that long, maybe an hour to tell if it's working.

If your fan's turning, and air's getting sucked in through the filter, your fan's OK (unless your housing's still leaking). If your filter's good, it should be able to handle the smell from 8-12 one-month-old plants, depending on strain, size, etc. within that single sealed room. If the fan/filter combo suppresses your odors, start reassembling your ventilation system one section at a time until you locate the component that's causing the problem.

If your filter's not breathing real freely your system may be creating enough of a vacuum to pull stinky air into the ductwork AFTER the filter, especially if you're overdriving the filter. That seems like the only way smells could be getting in there, unless the filter's just not removing them to begin with.

Now, if you've got a goodly number of plants going, you may just need that Can 66 (or more). I've been abusing the hell out of a Can 33 (with a 424 cfm on a speed controller) for a year and a half and it's hanging tough. :thumbsup:

FWIW, HTG seems a reputable firm and the "store brand specials" are cost-effective. Maybe you can trade up. Filters are heavy to ship, though.

HTH, Hermie