Massive fish die out

[KingAh123]

My fish all died in the matter of 2 days. First the gobies and royal gramma then my blue sapphire damsel then my bicolor blenny then clownfish and now my 2 tangs are almost gone.
Fish won't eat or anything, no visible illness like white spots.
Water seem fine:
0 ammonia
0 Nitrite
0.5 Nitrate
Corals and inverts shrimp, snails and hermits also doing fine.
The only thing I can think of is maybe it could be my frozen food brine shrimp that I began feeding again 2 days ago.
The other thing is I installed a new sump from an old tank which I cleaned thoroughly but wouldn't I be able to detect something in the water.
The has had an ocean type smell to it, like the same smell as algae dying. Which it has since I installed the sump.

 

[KingAh123]

Here is the dead clownfish I don't if this would help.

 

[alton]

Your PH?

 

[Mr. Mojo Rising]

Not much to go on...
How big is the tank and how many fish? When is the last time you added a fish? Are the fish QT'd?

 

[j.falk]

What did you clean the sump out with? Did you use chemicals or soap to do so?

Also, check your tank temperature.

 

[Shibaken3]

when was last addition of fish?

 

[Nemo&Friends]

I do not think it would be the brine shrimp. Most probably due to the cleaning of the added sump.
If is smell like dying algae, you may be lacking O2.

 

[KingAh123]

I do not think it would be the brine shrimp. Most probably due to the cleaning of the added sump.
If is smell like dying algae, you may be lacking O2.

The Purple tang is still alive, swimming around, not accepting food, though he did yesterday, hoping that he will survive. I have shut down the sump until I find out what is wrong. I have a suspicion I ran a canister filter before the sump some of the ceramic media I thought would be great as bio media in sump, so I transferred them all but now that I remember they had that same rotten smell to them. Furthermore, I cleaned the sump with just normal tab water and some vinegar, I was too scared to use any bleach or cleaning stuff.

 

[KingAh123]

Your PH?

8.1

 

[KingAh123]

What did you clean the sump out with? Did you use chemicals or soap to do so?

Also, check your tank temperature.

Temps has been at 26C the last couple of days since it has been hot it is now 25,3C. I did not use any chemicals or soap to clean the sump, since I was scared of it polluting the tank I did clean it with vinegar.

 

[KingAh123]

when was last addition of fish?

My last edition was the Tangs. Purple tang and a mimic tang 5 months ago

 

[KingAh123]

Not much to go on...
How big is the tank and how many fish? When is the last time you added a fish? Are the fish QT'd?

I did not qt any fish. The tank is a 375 liter with 125 liter sump.
Fish that has died, some of them year old:
2 occellaris clownfish dead
1 bicolor blenny dead
1 yellow watchman goby dead
1 diamond watchmand goby dead
1 green clown goby dead
1 blue sapphire damsel dead
1 royal gramma dead
1 purple tang still alive
1 mimic tang dead

 

[Andreas' Reef]

Any noticeable spots? Possible ammoodinium

 

[KingAh123]

Any noticeable spots? Possible ammoodinium

The only noticeable body change in appearance is the mimic tang had like big black bruises on his body, the other fish have nothing on them.

 

[brandon429]

You can't skip disease preps and be ok. See disease forum

 

[KingAh123]

I do not think it would be the brine shrimp. Most probably due to the cleaning of the added sump.
If is smell like dying algae, you may be lacking O2.

Another thing the ceramic media lied in the sump without being underwater for 3 days, maybe the cause is bacteria dying out?

 

[brandon429]

No that's not the cause

Skipping disease preps is the cause

 

[blecki]

There was another incident I saw recently where OP eventually figured out that he had food rotting in a tube from his auto feeder. It very well could have been 'rot' from that ceramic media. How long ago was this media added?

 

[Boreas_SA]

If you haven't added any fish in 5 months, the chances that a disease will be latent for so long and then kill all of them in 2 days is almost zero. Can you double check the ammonia with another test kit?

 

[KingAh123]

There was another incident I saw recently where OP eventually figured out that he had food rotting in a tube from his auto feeder. It very well could have been 'rot' from that ceramic media. How long ago was this media added?

I put the ceramic media in when I emptied the canister filter about a week or two ago the media has laying in the sump for about 5 days without any water.