text: Freshwater aquaria Peat is sometimes used in freshwater aquaria. It is seen most commonly in soft water or blackwater river systems such as those mimicking the Amazon River basin. In addition to being soft in texture and therefore suitable for demersal (bottom-dwelling) species such as Corydoras catfish, peat is reported to have a number of other beneficial functions in freshwater aquaria. It softens water by acting as an ion exchanger; it also contains substances that are beneficial for plants, and for the reproductive health of fishes. Peat can prevent algae growth and kill microorganisms. Peat often stains the water yellow or brown due to the leaching of tannins.
  Balneotherapy
  Peat is widely used in balneotherapy (the use of bathing to treat disease). Many traditional spa treatments include peat as part of peloids. Such health treatments have an enduring tradition in European countries including Poland, the Czech Republic, Germany, and Austria. Some of these old spas date back to the 18th century and are still active today. The most common types of peat application in balneotherapy are peat muds, poultices, and suspension baths.
  Peat archives
  Authors Rydin and Jeglum in Biology of Habitats described the concept of peat archives, a phrase coined by influential peatland scientist Harry Godwin in 1981.
  In Quaternary Palaeoecology, first published in 1980, Birks and Birks described how paleoecological studies "of peat can be used to reveal what plant communities were present (locally and regionally), what time period each community occupied, how environmental conditions changed, and how the environment affected the ecosystem in that time and place."