I was just curious, one guy said that the instructions on the bag said that you can reuse it. I didn't actually read the bag and wasn't sure if that was common practice, sounded a bit fishy to me too. I used to use sand as a substrate back when I didn't know what I was doing LOL and I would wash it and bake it out in the oven. Probably can't get Reptichip hot enough to kill bacteria without burning it up.