Dennerle Nano Active Carbon removes effectively pollutants, residues from medications, odors or colourations from the water in the nano cube. This super-active, high-efficiency filtering carbon is suitable for nano fresh water aquaria and any other frehs water aquarium. + pellet form for clean use and maximum performance+ pH-neutral, does not release any algae-friendly phosphates+ for crystal-clear, healthy water Mode of use for Dennerle Nano Active Carbon:recommended dosage: 10-20 ml to 10 l of aquarium water. Pour required amount into the Nano FilterModule of the Filter-Extension, then rinse thoroughly with tap water. Period of use: 2-3 days to remove residues of medical products, otherwise 7-14 days.