Hyuga Pumice Bonsai Soil Component - gallon bag
Pumice is what many pros and serious bonsai enthusiasts use as an important component in their soil. A favorites is a lava - pumice mix (this soilless mix is technically a substrate). Particles range from about 1/2" down to 1/16" with most 1/4" to 1/8".
Though you can use it as is, sifting is recommended. Once sifted you can use larger particles in mixes for large bonsai and smaller particles in mixes for smaller ones.
1 gallon bag