Super soil recipe for me

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.

You're gonna need over 5 bags (1.5 cu.ft.) of good base soil just to fill your pots 1/3 of the way up. It's always good to make more for top dressing later on in the season. If it were me, I'd just make a full batch for 8 bags. If you don't use it all this year, it'll still be good for next year. Remember, you wanna water it and let it set for at least a month before you use it. Good luck with the grow !!