I ran out of cat litter while cleaning out the litter boxes last weekend.
I went to get cat litter on Sunday, and the place where I went didn't have the usual stuff. I have tried one that they had, and while OK, it's a little expensive. I ended up getting something called "CatIt Clumping Litter" in the 18 pound bag. The bag filled a box a little higher than I'd intended.
I've been using 27# and 40# containers, and filling 2 boxes, then I'm out of litter. So I figured 18# would be a good amount for the box. I guess the volume is different in this litter, because I ended up with 6 inches of litter in the box!
So far, the cats haven't used the litter. Mr. Beasley is protecting the box from the girls, though. I think he's claimed the one in my bathroom.