I solved my space issue and want to do a similar setup. I do have space to go 40" on center, is that optimal? I have a couple of 600w lights, should I just add more 600w or reverse and get some 1000W? I would be at 3600w vs. 4000w? Will that make that much of a difference?
On your setup, I only see one aerator in the epicenter but later see an airline manifold, are there aerators in all the buckets?
Are you running a reservoir? And, if so do you have to modify the epicenter with a float valve?
Where the flip is the pump? I dont see how the filtered return line works unless its connected to the pump?