Medium (3/16″-5/16″) Pumice is solidified foam that forms from lava rich in gases. It has an intricate network of cavities that creates structure that is 70% porous and absorbs moisture well. The porous structure of pumice gives it some unique qualities making it useful for gardening. It has a low bulk density and is neutrally buoyant meaning it won’t sink to the bottom of the soil or float to the top. Horticultural grade lightweight Pumice is inorganic so it has no odor and won’t break down, decompose, shrink, compact, or rot. Added to garden soil, it will improve the soil making it more porous and improving aeration and drainage while maintaining a reduced soil weight. The perfect potting soil varies depending on its use. Each type of potting soil is specifically formulated with different ingredients whether the need is for better-aerated soil or water retention. Pumice is one such ingredient used as a soil amendment.Read more at Gardening Know How: What Is Pumice Used For: Tips On Using Pumice In Soil https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/using-pumice-in-soil.htm
