I purchased these metal containers to hold activated alumina desiccant and I originally put one in the center of each spool of filament. I found this to be tedious when moving spools around, and exchanging them between drybox storage and my AMS.

I instead decided to mount 4x cans to the lid of the drybox and that allows me to replace just the lid, which is outfitted with fresh desiccant. The old lid with depleted cans and the new lid with fresh cans can be swapped very quickly without letting too much humidity in. I used 3M VHB (very high bond) double sided clear tape to mount the clamps to the bin lid.

Activated Alumina recharges at 200degC or 392degF for about an hour. I like to bake the metal cans directly without needing to empty them.

If you place these cans inside spools in the AMS then they will rotate and tumble some. Since the alumina beads are not forcefully stuffed into the cans, the beads can jiggle around inside and make powder. To prevent this, I took a stainless steel scouring pad and used kitchen scissors to cut into golf ball sized pieces to stuff on top of the alumina beads when filling the cans for the first time. The scouring pad acts like a spring and when you screw on the mesh top to the can, the beads get squeezed and then they do not tumble around to make any powder. The scouring pad is able to take the oven heat and doesn't prevent moisture from getting to the beads.

I have been using the Govee sensors with great success over the past month. I am not sure, but it appears that the humity keeps decreasing. I think it takes some spools several weeks to give off most of their moisture unless you want to use elevated temperature filament drying.

I was able to stuff one of the Govee sensors into my AMS, but it had to be taken apart and reworked some. I published a thinner sensor frame that allows you to place it inside the AMS giving you wireless logging of the AMS conditions, something that most sensors cannot do.

Metal Cans: Amazon B0B4JWGTTT

2lbs Wiseorb Activated Alumina: Amazon B0B81VM24F

Sterilite 20Qt gasketed drybox for 4x Spools: Amazon B002BA5F3O

Govee High Accuracy Wireless Thermo-hygrometer with data logging: Amazon B0BQ6P8JLD

Stainless Steel Scouring Pad: Amazon B002CQTXBC

3M VHB Double Sided Tape: Amazon B00I4E4NE8