oic thank you.she was useing hartz old fashoined stuff in orange bag but i am outa town a lot so i figured i beter go get something better.she was so happy to see me today i was gone 3 days
I'd say that one should scoop it at least twice/three times a day...and then dump it all out at least once a week? 20 lbs...should last a cat a few weeks...but probably less than a month. Every once-in-a-while, you should add a cup full or two to replace the amount that is lost when clumping to the cat's 'duty'...but it should last you at least two or three weeks.
We use a 34lb bag every two weeks or so (but we completely empty the boxes every two weeks) with 4 cats and 3 litter boxes (using worlds' best cat littler which is a little longer lasting than regular litters)