Built a kitty litter scrubber and changed the exhaust layout.
I got one of those cheapy 6" Inductor fans and since I'm not using 6" duct, the 120mm moved more air with 4" duct. I figured 6" might do ok, but it didn't and it was a freebie anyway, they never rung it up.
Those scrubbers work AWESOME. I don't smell crap! or plants.
Next time I make one, I will use window screen material instead of pantyhose, I think it'll be more durable.