I don't know about all THAT, by the time I add in my Compost, EWC, Bio Char, and Bunny Poo, It's probably a bit more, but I have a FAR superior product, and it's a KNOWN factor. No variables. Plus I'm certain it's all organic. I pay $13 for a 2.8 cu/ft bag for soil, $9 a 25lb bag for the EWC, and I use 3 of each of them every grow.
