It depends on what you use it FOR. Seriously—when I forget to change it even within the hour, the hot beverage result LOOKS like coffee but weaker than tea and not fit to drink. For drinking, ground coffee can be used once. You might be able to re-use it for something else besides drinking—like to get epoxy or gorilla glue off your hands after its used—or for a facial scrub or maybe its good for the plants.