Hey Dr. Who subs super soil is not prepared from scratch....your actually just re amending already amended soil.......it's decent but it runs really hot and pretty pricey to make if you use roots organic......I started organics by following sub but after about 2 years I got tired of buying bags of roots @ 25 dollars a bag so I started researching and found how to make my own from scratch in the
https://www.rollitup.org/organics/636057-recycled-organic-living-soil-rols.html for a lot less.The best part is that you can recycle this mix over and over and results get better with each recycle.....An example of the mix I use below......
1/3 sphagnum peat moss (premier @ lowes 9.99 a 3.5 bale)
1/3 quality worm castings
1/3 perlite/rice hulls/pumice
then add crab meal, neem seed meal,kelp meal and then rock dust......I also add a little alfalfa meal and gypsum