Bamboo charcoal pieces that are handcut to be added to tap water. Pieces should be rinsed and boiled prior to adding to tap water for effective use. Because our bamboo charcoal is handcut, sizes of tiles will vary depending on weight. On average, three pieces of bamboo charcoal should be added to one liter of water. Rinse bamboo charcoal and boil for five minutes before adding to tap water. Replace every 4 weeks or every 150 liters of water used.