Hi mcruderalis,,,gotcha. I grow outdoors in 10 gallon pots. I use Dr. Earth Pot O Gold potting soil which has all that kind of stuff in it already. Can't really say if the mycowhatsises really help or not, but I know they don't hurt. My roots are always really healthy. I had one bag left over from my spring planting that I was going to use to replant some lavender for my wife a month or so ago, so it had been sitting for months. I opened that bag up and was greeted by an astounding mass of very strange looking fungi growing throughout the bag but mostly on top. It didn't smell bad and was all the dirt I had, so I dug out all the weird fungi and went ahead and replanted her lavender. The lavender is doing fine. I would not have used it for my cannabis though.
I take it from your handle that you grow autos, mcruderalis? Indoors? In what medium?