CocoTek organic growing medium consists of three different types of compressed coco coir. This high-quality, low sodium growing medium is an environmentally-friendly alternative to sphagnum peat moss. When hydrated with water, CocoTek rapidly expands, saving time and effort. General Hydroponics CocoTek growing mediums can be used exclusively by themselves, blended together or mixed with expanded clay pellets, perlite or topsoil.