How long do you have filament sitting “in the open”? I mostly print with a single filament roll at a time, and just leave it on the printer. A 1kg roll lasts me several weeks. For long time storage I keep it in an air tight box with disiccant pouches.
But how long can I let it sit before I should start storing it with disiccant and/or drying the filament before use?
All my active rolls are in dryboxes with a bunch of dessicant, I’m probably going to try setting up a solution that lets me use even more dessicant. I use a dryer for new spools, even sealed stuff can pick up moisture for things like petg and definitely stuff like nylon. I printed 4 of these https://blog.prusa3d.com/dryboxes-and-alternative-spool-holders-not-only-for-multimaterial-upgrade_30525/ with these to support to spools https://www.printables.com/model/445085-ptfe-tube-roller-for-drybox and some Bowden hookups +some dessicant inserts
I live in Canada, it gets super humid in the summer so I find I’m having to change dessicant often, don’t open more than I need to.