You are at the higher end when it comes to bioload.
Have you changed your lights out yet?
Also look at the water. The "DI" really means a lot for a reef tank.
What kind of
skimmer are you running? Do you feel it pulls the gunk out really good? Everything IN must come OUT- is that happening?
I prefer to work out issues like this the natural way before adding "phos" this and "Phos" that to the tank.
