Diatomaceous earth (DE) is a natural substance that consists of the fossilized remains of diatoms, a type of algae. DE has many benefits for bonsai cultivation, such as improving drainage, aeration, and pest control. DE can be used as a standalone soil or mixed with other components, such as pine bark, pumice, or lava rock. DE is also pH neutral and does not degrade over time. However, DE should be sifted before use to remove any dust or fine particles that can clog the pores and reduce water retention. DE is a good alternative to akadama, a clay-like material that is commonly used in bonsai soil, but may be hard to find or expensive in some regions.