Supersoil for my exact needs

I am gonna be doing two 65g pots and 1 45g pot outside. I have read subcools recipe but it's for 7g plants?

I wont be transplanting outside for another 3-4 weeks. I'm in northeast so we harvest beginning of October normally. I want to beable to transplant my 1 month old plants into this soil and ONLY WATER.

How do I figure out how much I need of each ammendment? I know 65g is roughly 8.3 cu ft.

Can i use promix as my main soil?

175 gallons total for two 65's and a 45, so take that 7 gallon recipe and multiply it by 25 to get 175 gallons of SuperSoil.

I'd use a coots mix variation before I used subs super soil, it's going to be alot cheaper since you have so much to make.