Hydroponics grow medium Coco (Coco Coir) is derived from dried coconut husk. Coco offers structural support to the plant roots. Although coco coir is organic plant material, it breaks down and decomposes very slowly, so it won't provide any nutrients to the plants growing in it, making it perfect for hydroponics. Coco is ph neutral and has a high water retention capacity while allowing for a good amount of oxygen for the roots. Coco is mainly used in container gardening and passive hydroponics system. It can be used in expandable drip and flood and drain systems but not ideal as it is dirty and can clog pumps and drippers. It is available as loose potting material and coco bricks.