Bumping this up. New grower here and I've spent a good $500-$600 for a small indoor grow. I'm getting close to my very first flower right now and my humidity is hovering between 60-65%. I've been looking at discussions on this site for the last month or so to get tips and was looking for a cheap way to get the humidity to a more flower friendly level and saw the cat litter thing. I assume you want clay based cat litter as it's super absorbent. I just made a make-shift dehumidifier inside my 2x2x4 tent and what I did to make it was just simply took a bottle, drilled holes down the sides of it until I reached about an inch from the bottom so should there be water build up, it wouldn't drip everywhere, and I filled it with the clay non scented cat litter and hung it up in the tent via plant ties *like bread ties but for LST*. I plan on hitting flower Monday night so I will keep everyone updated as to if this is even remotely worth trying.