"Activated carbon pellets for salt and fresh water aquaria carbolit is a highly efficient activated carbon manufactured in pellet form. carbolit quickly cleans up aquarium water, removing colouring substances, turbidity and medication residues. Yellowing substances that may accumulate in the water are also removed. carbolit may also be used as a long-term filter material. After a short period, bacteria settles on the pellets making the carbon act as a biological filter, both aerobically and anaerobically. carbolit is pH neutral and can be used in salt and fresh water aquaria."