RBTA dying???

[apexifd]

8 months old, SPS tank. corals are happy.

yellow tang, powder brown, kole tang, fire fish, 6 line wrass. cleaner wrass, cleaner shrimp.

2 X 150w MH, 4X54w T5. mp40 X 1, korollia 750GPH evo X1. ca reactor, vertex in-100.

ph. 8.1
kh 11
Ca 380(boosting it up)
mg 1300