If the carbon CAN be replaced I've heard anywhere from 6 months to 1 year. hope you hit the 5# mark man! thats my goal for this run as well
I just basically let convection play a role in deciding to put my filter at the ceiling, technically the air at ceiling height is going to be warmer, so it's dual purpose in my case at least, let me tell ya though, it wasn't easy to accomplish, I would definitely recommend using 4 ratcheting tie-down straps and use the ratchets to raise the filter in sequence