Marfied Controsoil (Japanese Soil)Authentic high grade Japanese soil, made from premium source material with trace elements and buffering content for all planted aquariums and shrimps. Controsoil is a multi purpose soil that is volcanic in origin. It lightly acidifies and softens aquarium water to create an environment conducive to Fish, invertebrates (including shrimp) and plants that must be maintained in these conditions (e. g. aquatic organisms originating in Tropical rainforest