Help with new 190 gal build

[coralor]

And Mark, WOW!! I just read thru your tank build and it was VERY helpful! (And gorgeous) Thank you so much for sharing!!
I do have a few questions:
I noticed you had your returns come up and over the overflow but I was planning on having the overflow as a coast to coast and the returns situated on the outside edges. And a Maxspect Gyre maybe 280 on the inside.
I was hoping that would be enough total flow for the whole tank?
And concerning your SPS loss, did you ever figure it out? I had a similar issue that was due primarily to low Alk and now things are much better.