A clean litter box makes for a healthy and happy cat. We recommend replacing Modkat Reusable Liners when there are signs of fraying, or after 3 months time to keep bacteria and odor in check. 

The integrity of the liners depends on how many cats use the litter box, how much litter is used, and how ferociously they scratch. Daily scooping and sustaining the litter level at 2-3 inches (5-7.5 cm) will maximize their life.