Kanuma Pumice is produced in the Tochigi and Ibaraki areas, with particularly high quality soil yielded in the city of Kanuma, hence the name Kanuma soil. Its geological name is Kanuma pumice, and its primary components are silica and aluminum. It is acidic (pH 4 to 6), and mainly used for succulents, satsuki azalea and rhododendron bonsai. It is a rare material, produced in the volcanic mountains, is generated by the lower volcanic soil, in the form of volcanic sand, PH is acidic, has a high permeability, water retention and ventilation, trace element level is ok, but not as Akadama. Kanuma Pumice is not very uniform in size and has many holes. Personally, I do not like to use it as paving soil because it is too easy to pulverize the granules.