Nutrients dispenser for plant hydroculture esp. for surface use - is closed-pore structured medium impregnated or soaked in nutrient

摘要

Dispensing material for plant nutrients or other active substances consists of particles or pieces of a material of predominantly closed-pore structure, filled with the nutrient or other substance. The particles may be of expanded clay or expanded shale, and impregnated with the nutrient substrate or they may be of a granula material. Mixtures of various types of particles may also be used.