For its photosynthesis the Curled Hook Moss  Palustriella commutata removes carbon dioxide out the lime (calcium hydrogen carbonate) which is dissolved in the water. So crystalline lime (crystalline calcium carbonate) is precipitated, which can accumulate on the moss, whereby imposing tufa rocks can build up over the course of some years, like e.g. the sinter terraces near Berching-Holnstein west of Regensburg in Bavaria shown on the first photo. The famous waterfalls of Plitvice and Krka in Croatia with their lakes one behind the other have also been created this way.