Mysterious disease

[michika]

We've never treated copper in our tank.

Most recent fish added were a foxface, and a male mandarin. The male mandarin passed away yesterday, Thursday. The Signapor Angel died on Monday, and today, Friday my Lemonpeel was gone.

All readings are normal
SG at 1.024
pH 8.2
Alk 9dkh
Ca 400
Nitrate 10ppm
Nitrite 0ppm
Ammonia 0ppm
phosphates were 0.25
All water changes etc is done with RO/DI

All our corals are starting to flourish again, all the polyps are out and extended. Figures, I have a bad rash of coral die off in which I lost 90% of my corals, and now my fish are dropping off.

I wonder if a lack of cleaner shrimp could be contributing? We've always had cleaner shrimp until about 2 months ago.