Jurassic Sphagnum Moss 20g Sphagnum Moss is a versatile and extremely important component for many terrariums and vivariums. Completely free of any impurities and contamination, it is essential as a humidifier material, an incubation medium or as a substrate for live plants. As an invaluable humidifier, it can hold moisture up to 20 times its dry weight and unlike other organic matter in humid environments, it does not decompose quickly. Substrate of choice for Jurassic Natural Bamboo Humidifiers.