I would just use your own discretion. We have used it in the past - you have to soak it I would say every 3-5 days depending on your tank style. I just re-used until a next big monthly clean. If you snake were to excrete urates or feces on or near it then I would chuck it. We bought the Zoo Med Terrarium Moss and you really just need a chunk - no need to use up the whole box.