I recently stayed in an apartment that didnt have central air so I created a corsi-rosenthal box since the smoke from the Canadian wildfires were so bad.
After 30 days of continuous use, with very minimal periods of it being turned off, this is what the filters look like!
It's disgusting yet also so satisfying to see the filters get darker from debris, dust, and dirt.
Edit: typos
These have been around for a long time as DIY filters for folks, I remember seeing one of these on Reddit before comments were a thing.
Once upon a time Reddit drove you to interact with other websites instead of shitposting your best hot take about the title of the post someone else didn’t even visit.
Comments truly ruined Reddit
Long time ago I made my own activated carbon filter from plans I found online out of chicken wire, some duct parts, of course activated carbon, and pantyhose. got some funny looks when buying that last one, but it worked like a freaking charm.
custom filters are common in the aquarium hobby, lots of fun pipe fittings to play with