The Two Little Fishies MetaSorb High Capacity Metals Absorption Cartridge Filter is a high capacity filter for removing metals from aquarium water. It can be used in our PhosBan Reactor 550 with a Cartridge Adaptor. This is primarily of interest to public aquariums but it is also meant for use on larger home aquariums with metals problems. The popularity of ICP testing motivates people to actively reduce excess metals when their water becomes contaminated. The cartridge format can be run continuously, unlike the pouch version, which has to be removed after 1 week to prevent the pouch from decomposing.