Just Right Xtra is teaming with beneficial microbes, bacteria and fungi. General Hydroponics has included Cocotek coconut coir, Ancient Biology Alaskan Forest Humus, Subculture M mycorhizae innoculant, Subculture B probiotic inoculum and Rare Earth prophylactic clay. This mix also contains the finest worm castings, natural organic potash and organic bone char. Just Right Xtra has a perfect pH of 7.01 to keep the bacteria and fungi perfectly happy and healthy!1.5cu ft