help with fish losses

[pascal32]

One of my friends has been loosing fish over the last 2-3 weeks.

tank:
180 reef
240 fish only
shared sump
GFO
Carbon
Lanthanum doser (as needed) to 5 micron sock
vodka dosing
skimmer
automatic water changer
ReefKeeper for ATO, temp, etc

levels
phospahate .7-1.2 (hanna checker)
salinity 35ppt (calibrated refractometer)
nitrates < 1
KH 10.5
temp: 78.5

history:
* added 2 clowns about 1 1/2 months ago
* added 5 yellow tangs about a month ago, one died within a few days
* there was a lanthanum overdose about 3 weeks ago that made the water cloudy, yellow tangs breathing heavy, recovered
* there was a lanthanum overdose about 1 weeks ago that made the water cloudy, no distress noted
* over the last month 4 yellow tangs (added a month ago) have passed on.
* full grow fusiliers are showing signs of illness, one has died
* two clowns passed today

some of the fish are starting to look pale. corals look OK, have been having a hard time getting the "juicy" look back, that started 3-4 months ago.

We have been running the lanthanum for 6-8 months with no issues. recent overdoses of lanthanum are due to checker which was not reading correctly (dosing while phosphate was too low)

here is a picture of a fusilier. any thoughts?

 

[humaguy]

did the fish go thru qt?
did the fish that died have same lesions?
seems like you started losing fish after the new ones were introduced...

 

[pascal32]

the fish did not go through QT (yes, shame shame shame). The losses appear to be associated with the introduction of new fish. All the fusiliers are showing similar signs. some of the other fish which have died did not.

A recent observation, the fridge used to hold the frozen food is thawing on and off (keeping a freezer/fridge in the garage has it's downside). The now bad food has been discarded. fish seem to be rebounding a bit with the fresh food.

any thoughts on the picture posted above?