Seachem CupriSorb Powerful Adsorbent of Copper and Heavy Metals for AquariumsCuprisorb is a powerful adsorbent of copper and heavy metals. Cuprisorb will remove copper more rapidly and efficiently than carbon and is thus ideal for emergency copper removal. It extracts All types of copper, including chelated copper, and remains effective until it turns a deep blue black color. It may be regenerated repeatedly. If placed in continuous use, it will gradually extract even precipitated copper from the gravel substrate bed as well.