Hydroton is a type of lightweight, expanded clay aggregate used primarily in gardening and hydroponics. It consists of small, round pellets that provide excellent drainage and aeration for plant roots. The pellets are made by heating clay at high temperatures, causing it to expand and form a porous structure. This material is often used in container gardening and aquaponics systems due to its ability to retain moisture while allowing excess water to drain away. Hydroton is pH-neutral, making it suitable for a variety of plants, and can be reused multiple times after proper cleaning.