Vent problems since carbon refill

Recently changed the carbon in a 1-year-old carbon scrubber. Now the pressure of the exhausted air is very low. Before I changed the carbon, there was a negative pressure in the tent. Now the air coming out of the exhaust feels aobut that of a bad muffin fan. A little bit of air is being exhausted, I can feel it, it is just so much less that before I changed the carbon. If I take the scrubber off, the system works fine. Noticed that the little threaded plug lost a nut when I unscrewed it (that's what she said.) THe nut must be somewhere in the carbon now, but I can't imagine it would cause big problems.

Any help would be appreciated.

Sounds like maybe you should shake the filter a bit and loosen up stuff, it may have settled and packed in, causing restricted airflow.

Also, try to make sure it's SEALED all the way around when attached. leaks will cause quick and deep drops in pressure.