California pumice is a versatile component of many bonsai mixes. It can be combined with lava and akadama to create an all-purpose bonsai mix, or it can be used alone for recently collected trees. It makes a good drainage layer for all bonsai. It’s lightweight and resists breaking down with time. A note about the sizes: the small runs small with most particles between 1/16″ – 1/8″. The medium is the most popular for small and medium sized bonsai and runs between 3/16-5/16″. The large size is slightly bigger at 5/16″ – 7/16″. Volume: 13 liters W