Eheim Torf-Pellets -natural acid peat is rich in valuable substances, such as humic matter and trace elements. Eheim peat pellets reduce the pH value and the carbonate hardness of the water, and are suitable for all water conditions from tropical clear water to blackwater, in particular. Eheim recommends 1 litre of peat on 80 to 100 litres of aquarium water. Peat expands in water. For this reason, irrigate the peat (but avoid leaching) prior to use. Replace the peat after three to six weeks. Do not use peat and activated carbon at the same time.