The lime or calcium carbonate in the substrate serves the adjustment of the pH suitable for plants, which allows all nutrient elements to be optimally available if possible. In general, this lies between 6.0-6.8 (H2O) or 5.5-6.3 (CaCl2). The acid loving bog plants are an exception. Finely ground carbonated lime is mainly used for substrates. Dolomitic lime contains additional, valuable magnesium.