Growing out corals.

[adam84]

Other than lowering your nitrates my suggestion would be to keep your lighting high but lower the length of time at 100% try to replicate natural sunlight starting the day with only the blue spectrum for an hour or two then the whites and then full spectrum for only a few hours and ramp back down. I have been using led for a few years now and what works well for me is I start my blue channel in the morning for 2 hours then the whites come on, 1.5 hours later I have 3 T5s that come on for 4 hours (2 true actinic 1 coral plus for a more full spectrum light) 1.5 hours later the whites are back off and it's 2 more hours of just blues.