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?
So i live in Germany, and i just put a bag with silica over the active roll and call it a day. But it depends very much on the material you print with, i print PLA and that dosn’t pull much moisture out of the air.