I don't really keep track of how often I dump the clumping litter. Possibly 4 times a year (maybe only 3 ). I use the cheapest stuff I've found. It is called Premium Scooping Litter. It comes in 40 pound bags At $6,98 each and I usually buy 3 bags every month just to top off the boxes. I only have odor right after someone poops and doesn't cover . The fosters have to use clay due to the babies and I am dumping that about every day or two.