Keep your eye on po4 while dosing nitrate since it should lower each time the tank uses up the new nitrate addition. I think it's time you add a few extra fish, that could help get some better nutrients to your corals. Tank looks great though, what exactly happened to your coral that you don't like color wise? What are you using to supply the big three and other elements? Color isn't always linked to nutrients showing up on a test kit.
