I have a few questions.
I don't understand the U shaped cooling thing. Can you post a pic in action?
I'll try to find a pic. There are 4 lights. The fan just sits in between the 2 rows. One side of the lights gets air "pulled" through it, and the other side gets air "pushed" through it. Far more efficient then sticking it at the end, etc.
You don't mention what size of pump you're using. Are you not having problems draining? I run 4 "pod" systems with dual 3/4"drains in series like yours. When I tried the first system (feed is a 1/2" line feeding 2 1/8" feedlines per pod) with a 350gph little giant the drains couldn't keep up. the last pod would overflow very soon after turning on the pump. I dialed the voltage back to 70 using a variac. Now I just run 160gph pumps for feed and am using 1-1/2" drains and larger tubs. Didn't have any clogging issues with the 5gal and 3/4" drains though.
I'm using a 500gph pump. There is no issue of draining. Because everything is on the same plane, there is no way that a 1/8" feed line can overpower a 3/4" drain. I just pulled about 14" of roots out one of my drains, despite root guards.
And finally,
Where are all the lights? Do you just raise them for the pics? Are you keeping them REAL high to induce stretching? What's up with that? Will they eventually be hung vertically in amongst the plants?
Picture shows the lights. They had way to close of node growth, so Ive been dumping them with nitrogen and raising the lights. I want them to stretch since i am still going to screen.