What do I do with the used filter? Please keep the sarcasm to a minimum… 
Makes me smile. 
Are you referring to the used filter element or a filter unit you don’t need anymore?
The used filter element, but the hubby is looking into venting solutions, so I may have a filter unit for sale in a few weeks.
It’s an old trick to hang disposable pie pans in the garden to scare off crows. Maybe a used filter will both be a crow deterrent and the burned forest smell might keep the deer out. Plus, since the filter is so expensive, it screams that you are an upscale redneck.
Too bad we just got rid of the double-wide!
It’s in the manual for the filter.
Toss it in the garbage.
We don’t collect the filter cartridges for recycling or to repurpose them. Feel free to dispose of the used cartridge in the garbage.