Akadama Ibaraki Double Red Line Substrate (5-8mm) 14LBoost your bonsai's growth with a professional quality substrate: Akadama Ibaraki Double Red Line (5 8 mm). This 14 liter bag contains selected coarse grains of 5 to 8 mm, the preferred grain size of expert growers for a perfect balance between drainage and moisture retention. Its reddish hue not only enhances the surface of the substrate but also reveals its Japanese clay origin, a guarantee of tradition and effectiveness in bonsai cultivation.