Have two cats and we are used to changing litter a lot.  This crystal litter states that you only need to change it every 2 weeks for 2 cats or once a month for 1 cat.  It's true.  If you remove the solid waste, it will last the a bit over 2 weeks for 2 cats.  We didn't notice any smell.  In fact, I think not having the usual litter smell is an improvement.  Recommend!