Mother Earth® Hydroton™ is a unique, lightweight expanded clay aggregate. Made in Europe, Mother Earth® Hydroton™ is ecologically sustainable as it is derived from a replenishable source, clay. Clay is mined, formed into pellets and fired at high temperatures to cause the clay to expand into lightweight balls that are porous but do not float like perlite. Clay naturally has balanced capillary action to accelerate plant growth with an ideal surface for root structures and beneficial bacterias. Mother Earth® Hydroton™ drains freely, is pH adjusted, free of harmful heavy metals and inert. Each batch is tested before bagging to ensure highest quality. You can use Mother Earth® Hydroton™ as a top dressing for moisture retention in outdoor landscapes as well as mixing in with container gardens to increase aeration and drainage. For best use, rinse before planting.