The Aqua One 106c Carbon Cartridge is a disposable filter cartridge for use in the Aqua One EcoStyle 61 aquarium. The Aqua One 106c Carbon Cartridge is a disposable filter cartridge for use in the Aqua One EcoStyle 61 aquarium. A pack of two is supplied. The Aqua One 106c carbon cartridge forms the first layer of the filtration process and the cartridge should be removed and discarded when blocked with fish waste and debris. This will usually be every four to six weeks. The Polymer ‘wool’ layer traps debris while the activated carbon removes odours and clarifies the water. An essential part of the Aqua One filter system.