CocoTek¨ Premium Coir is naturally free of bacteria, plant disease, fungal spores, weeds, seeds and pathogens. General Hydroponics¨ CocoTek¨ growing medias can be used by themselves, blended together, or mixed with expanded clay pebbles, perlite, topsoil, or any other growing media. CocoTek¨ Premium Coir contains pre-treated coco coir and can be used by itself or blended with other media to create your ideal mix.