Things went from bad to worse with my system and several pieces of SPS stripped, I really was at a loss.
The issue was, as My ICP test confirmed was metal corrosion or residue from my Chiller coil.
please see this
thread if you are interested.
ICP 1
It meant high Chrome, Zinc and copper. I ran Triton detox to remove the copper and performed some large WC to dilute the metals and will get the coil replaced with a better one. Unfortunately I cannot rule out having to rip the coil out at some stage and revert to a brand name indoor chiller such as Teco. That will be an expensive change

.
Anyway things are looking up for the corals at the moment with colors returning on the surviving SPS and some polyp extension appearing. I am even seeing encrusting growth at the bases of some pieces.
The issues had not stopped there as my fish who had been fine were affected by the changes and ich reared its head. I lost a very pale and sick foxface during this time.
Finally the coralline I seeded my tank with from another tank may have been seeded with a strange brown turf algae. This has dominated my rock work but I believe it will fade with time.
If i could change anything it would be better care for the fish, I have not lost a fish to ich in all the time I have been reefing and believe a healthy fish will overcome this parasite. on this occasion, with all the other factors. I lost a fish which is hard to take.