The ultimate Ebb & Flood mix! 60/40 is an exclusive mix that offers the free draining capabilities of clay, with the moisture retention and rapid rooting properties of coco. The combination of Gold Label 8-16mm clay pebbles and coco substrate provide a free draining, stable rooting structure that is pH buffered and has a very low EC; offering maximum control over nutrient content. This mix is RHP certified; rest assured of the highest quality. Free draining root zone – plenty of oxygen to the roots and no nutrient build up