gorgeous tank, I wish I had found this thread sooner.
Just a comment on your plumbing, because I have a very similar set up and have found a flaw in my own. The check valve position is great to prevent back flow into the return pump... however you will get some back flow into the reactors you have on the manifold. It will be a very slow trickle but if the return shuts down for any reason you'll have back flow through the reactors. If its just for feeding no big deal, but careful if it ever shuts down could flood the sump depending on water level.
Your wrasse collection, and previous tanks, are gorgeous.