The Black+Blum Water Filter contains four traditional Japanese binchotan charcoals, designed to be used in your Eau Good Duo, Eau Good Bottle and Eau Good Glass bottles, and will make your tap water taste fantastic. Binchotan active charcoal has been used in Japan since the 17th century for its ability to remove contaminants to purify water. It naturally filters tap water, adding good minerals such as calcium and balancing the pH levels. It absorbs unpleasant tastes and odours such as chlorine and softens water. Simply place one in your bottle and fill up with tap water. Wait for the charcoal to filter the water, overnight is best, but you will notice the difference after only one hour. When the binchotan is used once a day, one charcoal should last for three months. It can then be recharged by simply boiling it in water for ten minutes and leaving to dry in sunlight. It should then last for a further three months. Enabling you to reduce your consumption of single-use plastic water bottles, the innovative water bottles and filters offer a great choice for a natural, healthy and sustainable water drinking experience.