Are you planning to have all the powerheads all the back panel? Why did you choose to run two returns? And aside from equipment, how are your corals and clams doing?
Congrats on a fantastic build!
No... the way the aquascaping is coming together I will have channels coming form the back to the front at diagonals in the tank. I plan on having the power heads point down these channels, so at least one of them will be on the right side of the tank. I'm sure I'll have to play with it once I set it up, but that's the general idea.
I decided to go with 2 return pumps for a few reasons. First, redundancy. If a pump fails, the other one is still firing. And though I havent done this to date, I'm considering changing how one of them is wired to put it on an entirely different breaker (currently sump hardware is all on one breaker, but the Tunze units are on a different one so I won't lose all tank flow if just one of those breakers fails). Second, this also allows me a little more flexibility in terms of plumbing in other hardware (calcium reactor, chiller, carbon reactor, future reactors, etc.). Instead of having all the head loss for those devices on one pump, I'll split it up, which in theory should give a little better flow performance (considering that head loss affects pump performance in a non-linear relationship). And third, I already have two mag 9.5s.
Current livestock is "surviving." My LPS are doing wonderfully, as are the clams, but many of the SPS are tired of living in a poorly established stock tank (that has badly designed flow and nutrient export parameters). I havent lost much of my SPS, but they arent performing well and I do expect them to grow much better once I move them over. Of more significant concern is the recent increase in algae, particularly lobophora and some small patches of hair algae. It's no coincidence that the hair algae issues are primarily isolated to areas of woefully insignificant flow, and I don't suspect that to be an issue in the next 6 weeks once I transfer everything over. Lobophora, however, grows well in all kinds of conditions (including high flow... it covers the top of both of my tunze 6100s in that tank), so I'll have to apply other solutions for that nuisance (I had a blonde naso tang from liveaquaria which eradicated the lobophora about 4 months ago, but once it did so I believe the fish starved to death; I intend to get another that will hopefully take to a more captive diet as well as a taste for lobo).
I'd probably also complain about the lighting on that stock tank... I received an Icecap Reef Illuminations fixture as part of a review program which, at first, seemed like a good match. That fixture and the tank are both 4 feet long, it had a pair of 250W metal halides as well as two LED strips and two T5 bulbs. However, my long-term diagnosis is less positive. The reflectors in the fixture are pretty poor. They're also positioned near the ends of the fixture... not at all where you'd want them to center it over a 4 foot tank. As a result, I think I'm wasting a lot of potential out of the bulbs (14kK phoenix). So any acros I have that are not directly under those bulbs have suffered. I'll have to re-evaluate how I have that set up once I move the stock tank and get everything better situated for frags/QT purposes.