Help, Fishing Dying!

[dland]

Need help, although it's probably too late. We have a two year-old 90gal tank. Water params as follows:
Ammonia - 0
Nitrite - 0
Nitrate - 0
PH - 8.2
SG - 1.023
Ca. - 460
Temp - 78.1
Mix of lps and softies. Until last Fri. it was stocked with a flame angel, hippo tang, yellow tang, & BTA. On Fri. we added a pair of True Percula's, and a Potters angel. fish were eating and happy through the weekend. I came home this afternoon to find the Flame angel, & Tangs on their sides at the bottom of the tank dead. One clown acting fairly normal, and one at the bottom seperate from the other, laboring to breathe and on its side.
BTA looks awesome as do all the coral. Only the fish are affected. I'm at a loss, any help would be appreciated.

 

[dland]

That title should read: Help, Fish are Dying!

 

[Dustin1300]

Sounds like someone was fighting if params are spot on?

 

[dland]

Thanks for the reply, but I can't believe they were fighting and they all died. I'm thinking along the lines of a sick fish, that got everything else sick

 

[Dustin1300]

I'm not saying that is what happened but you introduced a new fish and also did not have any params that are out of whack. Considering those and most likely a new fish would not have some terminal disease that would kill all the other fish SO FAST! Thats just my hypothesis....Many others on RC are much better at the hobby than myself but I've done much research/reading on the subject since entering hobby. Anyone else?

 

[Dustin1300]

What about oxygen levels? Just thought of this...

 

[screwsloose]

i would either lead towards an o2 crash of some sort(possibly temporary power outage?),electrical shock,fighting, or a faulty test kit and you actually have a parameter out of whack.

 

[Dustin1300]

Good mentioning....always forget about the electrical shock and could also be the cheap test kit that screwloose talked of!

 

[Dustin1300]

How are the rest of the fish doing now?

 

[dland]

Thank you all for the insight. All great info. I took a water sample to a lfs and the params were on with what my readings were. Will check the elec. shock theory. I'm at a loss otherwise.

 

[Dustin1300]

How are the rest of the fish though?

 

[dland]

One clown has survived. showed signed of distress for one night, but has since been fine.

 

[stevensun]

Do you have any leather coral dying in the tank? It happened to me once that a dying finger leather caused my fish to look stressed and breathe heavily.

Some coral excretes toxins when dying. Just my 2 cents.