1 tang down.. 1 tang hangin.

[To(meany)Tang]

Hey reef family. I'm looking for honest opinions/facts about my situation. All feedback is welcomed.

I have a 55 gallon reef which I have to update everyone on later but for now I came home from work and found my philippine tang deceased and my kole tang laying breathing super heavy. I have an air stone..I have surface movement/agitation with a fluval fx4 canister. Did some tests and the results were.
Nitrate 40 (api)
Temp 79 (hanna)
Ammonia 0 (api)
Nitrate 0 (api)
Salinity .028 (refractometer)
All other fish are doing great. Recent changes to tank are.
4 fish added 2 days ago
3 corals added 3 days ago
A couple pieces of old live Rock I had sitting out for a month.

As of now I just added a protein skimmer to up the oxygen and did a 10 gallon water change to bring Salinity down to .026. Can anyone rattle my brain pls. I know the Salinity was a stressor but what else would only cause the tangs to be affected and everyone else is ok. The tangs are 3 inches each. Thank you for your time and knowledge.

 

[vetteguy53081]

Would my fish be ok overnight or should I pull all the coral and treat right now? Luckily I have a Hanna with reagents from my battle with ich long ago. Can I just put the corals in a bucket with heater and air stone? Thank you for your love.

If other fish covered, you may have to act quick. Coral ok overnite but I would not go much longer without light and flow