Pumice Bonsai Soil
Pumice is a Volcanic Substrate that can be used over and over again as it does not break down.
Pumice is very popular amongst yamadori Collectors as the trees collected can be planted in 100% pumice to recover with fantastic results
When mixing pumice into a mix with other substrates you gain strength and vitality in your tree, better drainage, slight moisture retention and it prevents the soil mix from becoming completely broken down and anaerobic.
Pumice is a widely used substrate in japan along with akadama.