Fully organic, like a mud lake, natural material formed by the deposition of plant and animal materials for more than 10 000 years. It is a combination of tissue fragments of higher plants, pollen, sand, clay and various mineral solutions taken from the ground. Some mineral derived from dissolving in water due to the formation of deposits containing fragments of ash, food, biomass, clay, organic piasku.Część, as a result of anaerobic biochemical decomposition of biomass and its subsequent re-synthesis by microorganisms. ACTIVE 3-5 years.