Product Black+Blum's charcoal water filter sticks are the ideal solution for healthy, clean hydration. They make your water taste great by reducing chlorine, mineralising the water and balancing the pH How It Works Step 1: Fill your carafe or bottle with water and place your ready to use charcoal stick inside. Step 2: Wait for the activated charcoal to remove impurities. Leaving it overnight is the best option, but you will certainly taste the difference in just one hour. Note: even if your charcoal is broken, as its an organic element, it will still perform its job. How Long Does It Last? With time the effectiveness of the charcoal stick filter will decrease and affect the water taste. After 3 months, you can recharge the stick by boiling it for ten minutes then leaving it to dry in the sun.