Since I had a problem with the ammonia odor, I've switched to Feline Pine. It works great!! It's pellets are compressed sawdust. You put 1" in the box and clean out the solid waste daily (I check the boxes 2x a day with 8 cats/boxes). The urine is absorbed by the pellets and there is absolutely NO odor whatsoever. The stuff lasts in the box for approximately 4 weeks. I've kept track of the stuff by writing on the litterbox in wipeoff pen exactly when I completely changed the litter. Once it turns to sawdust, you just toss it out and start over. There is no tracking and it doesn't stick to the bottom of the box like most clumpable litters do. I swear by the stuff. My cats like it too. It's $7.99 for a 20 lb. bag. I've tried the cheaper brand of the same thing and believe me, you get what you pay for.