Clay Pellets clay pellets Clay Pellets (also known as Hydroton) is a type of growing medium, popular in hydroponic growing. The small clay balls provide great drainage and air circulation.Read more about Clay Pellets (CC BY-SA 2.5) Related Terms Growing Medium / Perlite / Vermiculite / Coco Coir / Rockwool << Back to Glossary Related Posts:Growing MediumHydrotonHydroponicsGlossary of terms (Dictionary)Grow Mediums - HydrotonStarting Out