Thanks for the suggestions guys.
I could unbulk the returns, and I may have been a little pessimistic about them as I could probably squeeze 10-11" up from the bottom as is (flexible return lines).
I think my biggest concern was having vortechs so close to the sand, I figured that would just push it all out of the way, but I'm using special reef grade anyways which is a little heavier than oolite.
I should consider the overflow waterproof box also. That could keep more options open.
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