Have you done a hydro grow before?
I grow in coco which is almost hydro but far more forgiving. If I mess up (and I do) then the plants will survive and come back from the edge. Everything I have read suggests that a pure hydro grow can kill your plants in a few hours. For example, a power outage (likely in the winter with snow and wind) of 24 hours will wipe out a hydro grow but coco will just keep on chooching
I don’t want to rain on your parade, quite the opposite in fact, I want you to succeed. Getting a couple of successful grows under your belt first might be a good idea. It’s going to suck if you spend all that money and time and don’t get a smoke at the end.
The tent sounds spot on, I also grow in a 4x4. But:
Do you have anything planned to control the temps in your reservoir? Too hot and your roots will rot
How many CFM does the fan move? Is the filter rated for more CFM than the fan? How many cubic feet is the tent? (4 * 4 * 8) Robert sends out an email that talks about this. 6" might be overkill, my 4" setup (running at maybe 50%) sucks in the sides of the tent - proving I have negative pressure
How many watts per square foot will the lights provide?
Again, I’m not trying to p*ss on your fireworks, I just want to see you succeed - Hydro will get great yields but requires attention to detail (and frankly is beyond me)