Added Info...... to revive the topic
Now that you are using the NPR ( Nitrogen Phosphate Ranching process) and Hawke's super floss for nutrient export, and have gotten your tank nutrients low, you may need some added nutrients to help pop the colors out of the SPS.
This is a result of my special blend of trace nutrients that bring out the SPS color...see attached....
It is my special blend of emulsified Cod Liver oil and clam juice. (amino acids and iron)
A few drops a day will brighten up your tank.