Rootgrow Hydro is a granular stimulator designed specifically for the hydroponic market, it contains beneficial microbes (mycorrhizal fungi and rhizobacteria) to help plants absorb nutrients more efficiently. It helps to stimulate root development, increasing the root surface area and nutrient uptake. This is a one treatment product simply sprinkled into the transplant hole or roll wet propagation plugs in it to give direct contact with the roots ensuring colonisation.