I think your water is too clean and starfing the sps.
Try temporary remove GFO offline and feed the coral every other day.
In about a week you will see the sps getting healthy again and some die off may occur for the one that too far at edge.
When po4 creeps up to 0.04, put the gfo back online with half the media you normally use.
If your skimmer on all the time, you may also want to stop 6 hrs a day, may be when off when you go to work and back on again when you are
at home.
Healthy sps should take the light spectrum from OR at 100% all channels at 20", assuming that you have 100% sps in that frag tank.
If you have other corals may want to dim white channel and blue channel 100%.
For sps I prefer to run OR at 100% and play with height adjustment to reduce intensity.
Hanging OR 12-20" above water will be good level when using OR for sps only, you will get about 300-500 par at this height, will be less on older unit.
Like softy said check to make sure all diodes are firing.