IME 50% on whites is much too high on that fixture. I ran mine 17" above the water. I had SPS die very specifically under the white diodes, especially when I first ran it about 7" off the water.
If you're worried about biodiversity, I'd add some of that really good cultured rock out of the keys. I think @alton knows the name of it.
Yea, visually the whites look very bright... Although the PAR measured out right. But there must be something to the conversation behind LED's being not so great sometimes.
I appreciate the idea of the ocean rock. I am an avid QT proponent and somewhat of a hypochondriac when it comes to this stuff. I try to ensure I don't add any pests or hitchhikers to my system if at all possible. This does seem to come with the disadvantage of being harder to obtain biodiversity though. That said, I have a Diver's Den acro with a big chunk of coralline covered rock with it. I am letting that simmer in QT for a couple months to let potential fish pests finish their life cycle. Once that finishes, I am hoping that may seed my DT with "ocean biodiversity".