Word up DGC it’s bones from Cornwall here. I’ve been having troubles with my carbon filter at week 7 onwards as my girlies are getting super stinky. Being in prohibition land this is a big problem. I’m not sure why it’s failing as the filter is brand new and the largest one I can buy for a 4” duct system but thought I’d do something about it and came up with this little hack that’s working great so far. First I took an empty food can and cut it to a height that’ll fit inside my 4” ducting. I pierced holes in the top half of the can leaving the bottom half hole free. I filled the can up with fabric softener and put it behind the vent that’s coming out of my wall. The theory being that the warm air passing through and over the can releases the smell of the fabric softener and it’ll cover the smell. And its working perfectly the smell of the fabric softener is so pungent it covers the smell lovely and the super dank smell almost complements the smell of the fabric softener. I used to have to sniff out the weed smell but now I just smell laundry which is also perfect for the sound of air gushing out my wall because now it’s just a tumble dryer😉. I’m hoping the fabric softener will be thick and chemical enough not to evaporate too quickly as there’s a decent amount in there too. I’ve done some scratchy drawings to help the imagination. Hope this helps out with those pesky smells for someone.