The Exo Terra Sub Stratum is a specialized substrate designed for use in bioactive planted terrariums. It is sourced from the mineral-rich foothills of the Aso Volcano in Japan. The substrate is made from natural volcanic soil that is formed from andesitic and rhyolitic tephra which provides it with high nutrient content making it ideal for supporting lush plant growth. One of the key features of the Sub Stratum is its porous surface which allows for excellent drainage and aeration. This promotes strong root growth in plants and helps prevent waterlogging in the terrarium. The substrate s friable and low-density structure further enhances its ability to support plant roots and provides an environment conducive to a flourishing population of beneficial nitrifying biological activity. The presence of beneficial biological activity in the Sub Stratum helps create a self-sustaining living terrarium ecosystem. This biological activity plays a crucial role in decomposing biological waste keeping the terrariu