128 5 gallon pots just doesnt seem smart or in any way efficient but its your way, my bad. So how many grams per watt is that setup producing? I just think its a little foolish to think your not wasting money on nutrients when using that much soil, maybe you have a hook at a soil producer or something. I know for a fact a 2CF bag of soil only fills 2.5 to 3 - 5 gallon pots properly so.....how many bags of soil is that to fill all those pots? 50 bags of soil would get you roughly 125 - 5 gallon pots.... I pay $28 a bag for FF or roots so it would cost me about $1400 to fill that many 5 gallon pots... I've used SOG method in a 4x4, 1 block of coco and couple bottles of botanicare nutes which cost me a total of about $100 total for the whole grow and produced halfway decent buds on my first go around. You must also be pretty resourceful and have somewhere to get rid of your used soil which itself is a royal pain in the ass. It looks to me and everyone else that you're a fool with a bunch of money, and you know what they say about fools and their $...
To the OG poster, if you are going to veg for 2 weeks and then flip a 3 gallon pot will be more than enough. If you want smaller pots you can use smart pots all the way down to 1 gallon without having to be worried about being root bound with that low of a veg time however I would recommend at least 2 gallon smartys at the minimum. Smart pots air prune the roots as they break through the sides of the pot and then start growing sub-roots off of that never getting bound. I'd suggest finding some of them and if you dont wanna fully invest in them at least get a couple to try out side by side, but they will require more watering that a normal hard pot but I cant say what your plants are going to be like, in your soil mix, these are all variables you'll have to figure out as you go along, but a 3G should be more than enough. I do agree with the dude above about bigger root zones and all that as they do produce bigger buds but once you get a few grows under your belt you wont need anyones advice and you will know what you need.
I went through a phase where I wanted to do a (smaller) SOG grow and set my garden up for that and actually started buying everything to go that route but kinda started seeing things different once I started learning about supersoil and larger plants etc.. not to mention once you go over 99 plants you will be charged with a federal crime if leo happens to stop by and you arent legal. But 4 plants per 1000/4x4 space is where I'm headed with supersoil. I run a 4x8 with 2 1k lights for flower, and a 4x4 for veg which doesnt work well for bigger plants let me be honest, but once I get my cycle going I'll be pulling 4 plants per month out of one side of my tent with a 2 month veg period on them. Its taken 18 months of nothing but reading and screwing up to get where I am so be ready for some let downs and mishaps, no one is a pro overnight, some people are I guess.
I would say just start growing and get your feet wet but try to not fall into the bullshit with snake oil products and all that, which is what I like so much about supersoil. You mix the shit up once a year or whatever and add nothing, water your plants and thats it. Drop them into that monster pot and for 4 months do nothing but train and water said plants, no mixing up nutes, no transplanting once they are in the big pots, no nothing....just buds growing without much work from you other than making sure the environment is right. Personally I think using properly mixed supersoil will make you a better grower simply because you dont have to think about any other bullshit aside from when to water and how much basically. At the moment I do not use supersoil just because I'm closing up my garden for the summer this month and I had a ton of bullshit products that I wasted my $ on to use/give away before I switch over, but at the moment I have to keep excel sheets to keep track of what and when I feed and all that bullshit, and I'm only working with 12 plants.