It can also be regenerated. It will change color from a pale blonde to a dark brown even black as it adsorb waste products. Once it is exhausted, it can be regenerated with a solution of bleach and water.Soak in a 1:1 bleach:water solution for 24 hours in a non-metallic container in a well ventilated area and away from children. Use regular 8.25% hypochlorite household bleach (non-scented, no dyes, do not use a splash-less bleach). Rinse well, then soak for 8 hours with dechlorinator per cup of water. Original color and full activity should now be restored .And it could be reused . | ||||||||