Carefully mixed with the finest coco coir, perlite and paramagnetic lava rock, Big City Hydro Mix is a premium blend for indoor hydroponic gardens. this organic listed soil amendment provides a perfect blend of water retention and drainage to support root growth and ensure higher yielding plants. Big city Hydro-Mix is triple-washed and PH buffered to ensure the finest quality. Available in 2 cu. foot bags and in bulk.