Lightweight expanded clay aggregate, a growing medium and used with the use with the soil. These are commonly used in hydroponic gardening. Clay Balls are made by heating clay to around 1,200 °C (2,190 °F) in a rotary kiln. The yielding gases expand the clay by thousands of small bubbles forming during heating producing a honeycomb structure. Due to the unique structure, clay balls allow gardeners to control the level of nutrients and humidity their plants receive throughout the growing process. Clay balls are inorganic, have a neutral pH value, are fungus free and do not rot.
