Peat pellets lower the pH level and carbonate hardness of water. It is recommended to use it for tropical forest aquariums : in the range from transparent to "black" ( Amazon). EHEIM recommends a dosage of 1 liter of peat per 80-100 liters of water in the aquarium. The granules expand in water, so they should be soaked ( but not washed) before use. The peat must be replaced after 3-6 weeks. It is not recommended to use peat simultaneously with activated carbon. Peat pellets should be placed in the filter after mechanical filtration or suspended directly in the aquarium in a nylon mesh.