I disconnected my filter today and hooked a speed controller to my exhaust fan. I had the speed controller on my intake to control neg. pressure in the tent when I first set it up. I now have neg. tent pressure again, with plenty of air flow. Don't need the filter yet anyway.
I don't think these filters are clogged, just starting to get a little normal amount of restriction from filtering the air, and these cheap 220cfm booster fans don't have enough power like they did when the filter was brand new.
I'm going to get a 440cfm exhaust fan to use with the filter when the girls start to stink. Those filters are expensive, so no need to pull air thru them until we have to.