EHEIM TORFpellets consists of specially treated natural acid peat. It consists of valuable components such as humic substances and trace elements (which is why it should not be rinsed out). With Torfpellets the pH of the water is reduced (acidification) and thus the hardness of the water is reduced. However, pellets should only be used when the pH value required for the species of fish maintained is exceeded. Peat filtration is especially suitable for black water.