, you have an insanely high bioload for a 150. With that much live rock, I'm guessing there is not a ton of open swimming space? High bioload will lead to problems. Too many fish can cause troubles. Those trates need to come way down though.
You've got some really cool fish, its just a lot. If I were trimming down the numbers, I would definitely lose the Vlamingii, Sweetlips and Powder Blue. The PBT because the are notorious bullies. The others because they get 2'+ and really belong more in a tank two to three times what you have.
Keep us updated. Hopefully its nothing too bad.