As Schuetz stated the Golden Rods work really well at controlling humidity.
You can even use more than one if you wish. I use an 18" and a 12" in mine. Yeah I know it sounds sexual, for the perverts.
The 18" came with the safe and has been working since 99, I added the 12"
because of John Lennon. "Happiness is a warm gun" And for B/U if one does
fail.
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