All fish dead in 3 days

[Docsb79]

75 Gal tank has been set up for about 10 years. Over the last few days all of my fish have died except my filefish. Shrimp and anemones seem to be fine. No visual signs on fish like ick. Any ideas on what I could be dealing with?

Temp 77
pH 7.71
Sal 1.026
Alk 7.7 dkH
Nitrites .25
Nitrates 54, always has run high

 

[gbroadbridge]

75 Gal tank has been set up for about 10 years. Over the last few days all of my fish have died except my filefish. Shrimp and anemones seem to be fine. No visual signs on fish like ick. Any ideas on what I could be dealing with?

Temp 77
pH 7.71
Sal 1.026
Alk 7.7 dkH
Nitrites .25
Nitrates 54, always has run high

Ammonia? Have you had any power failures?
Did you do a big Water change?
Any home painting, pest extermination nearby?

 

[theMeat]

Nitrogen bubble ?

 

[Sean Clark]

Since you have detectable nitrite I would presume ammonia. If nothing else has changed I would also have to presume that there is very little biological filtration.
Perhaps one fish died and that set off the chain reaction of ammonia that resulted in the other fish deaths.
Sorry for your losses.

 

[Docsb79]

Ok I'll go grab an amonia test tomorrow. I was thinking that but assumed that would have effected the inverts. No power outages or anything being sprayed around it that I am aware of.

 

[vetteguy53081]

What test kits are you using ?
Ammonia spike, stray voltage, predator, low oxygen are just some reasons you will get a sudden wipeout

 

[Coinzmans Reef]

If it was ammonia I think you would have spotted the distressed fish near the top, its hard to miss. Only once has this ever happened to me and every fish but the clown fish died. The disease took most of them in three days or less. I had a sailfin that hung on for two weeks but eventually scummed to what I now believe was Velvet. I did see signs of the disease and miss diagnosed it for a slight case of Marine Ich. I had fish with Ich before and most of the times it goes away, this was different. One by one my fish fell, I was thinking the clown made it due to the Nem he lives in.

If you saw any spots however small it could be Velvet and you need to wait it out for months before adding new fish.
I waited eight weeks or something like that, after I added two damsels as guinea pigs and a UV. One thing I noticed with the Velvet, the fish hid a lot.

Yes, Did you add a new fish recently ?

 

[moz71]

10 year old tank! Seriously doubt any ammonia spike from a dead fish!! Unless something accidentally put in tank to kill biological filtration than yes ammonia spike but dead fish would never do that. Geez I put enough dead fish in my tank just in each feeding alone. And had a large fish die on vacation and never experienced a problem. Not sure why people bring that up. Something else going on here. I would ask did you add anything new to tank livestock or other?

 

[Sean Clark]

10 year old tank! Seriously doubt any ammonia spike from a dead fish!! Unless something accidentally put in tank to kill biological filtration than yes ammonia spike but dead fish would never do that. Geez I put enough dead fish in my tank just in each feeding alone. And had a large fish die on vacation and never experienced a problem. Not sure why people bring that up. Something else going on here. I would ask did you add anything new to tank livestock or other?

This is why I presumed that there may be very little biological filtration in the tank.

 

[bruno3047]

This was the first hit on a search for “old tank syndrome“. You may want to Google it yourself for more information. BTW. I’m not saying this is what it was, but knowledge is power.

Old Tank Syndrome Revisited | Reef Builders | The Reef and Saltwater Aquarium Blog

In the mid-1990’s I wrote an article about something I was experiencing in one of my tanks and which I had seen in a few other tanks and dubbed it “Old Tank Syndrome”. This is actually kind of funny…

reefbuilders.com

 

[Docsb79]

Since you have detectable nitrite I would presume ammonia. If nothing else has changed I would also have to presume that there is very little biological filtration.
Perhaps one fish died and that set off the chain reaction of ammonia that resulted in the other fish deaths.
Sorry for your losses.

There is about 60-70 lbs of live rock

This was the first hit on a search for “old tank syndrome“. You may want to Google it yourself for more information. BTW. I’m not saying this is what it was, but knowledge is power.

Old Tank Syndrome Revisited | Reef Builders | The Reef and Saltwater Aquarium Blog

In the mid-1990’s I wrote an article about something I was experiencing in one of my tanks and which I had seen in a few other tanks and dubbed it “Old Tank Syndrome”. This is actually kind of funny…

reefbuilders.com

This was a very interesting read, I was surprised how much detritus was in the rocks when did a water change last night. Figured I'd do a bunch of water changes over the next couple weeks before I try and put anything back in.

 

[Docsb79]

If it was ammonia I think you would have spotted the distressed fish near the top, its hard to miss. Only once has this ever happened to me and every fish but the clown fish died. The disease took most of them in three days or less. I had a sailfin that hung on for two weeks but eventually scummed to what I now believe was Velvet. I did see signs of the disease and miss diagnosed it for a slight case of Marine Ich. I had fish with Ich before and most of the times it goes away, this was different. One by one my fish fell, I was thinking the clown made it due to the Nem he lives in.

If you saw any spots however small it could be Velvet and you need to wait it out for months before adding new fish.
I waited eight weeks or something like that, after I added two damsels as guinea pigs and a UV. One thing I noticed with the Velvet, the fish hid a lot.

Yes, Did you add a new fish recently ?

First fish to die were a clownfish and engineer goby and I noticed this when my carpet anemone(about 8 inches) spit the goby out since it was so big. I just assumed that it got them and added a new clown the next day. The following morning I had 4-5 more dead fish and set up the qt tank. Everything else was dead except the file fish by the time I got the temp and salinity right in the qt to move fish.

 

[Sharkbait19]

Although ammonia is possible, the fact that nothing died besides your fish leads me to believe that this was a protozoan illness of some kind. I would also suggest that the water was oxygen depleted, as this too can wipe out fish, but I can’t imagine why nothing else would be affected in that case…

To me, this sounds like a parasitic infection. Did you add anything to your tank recently? If so, what was your quarantine procedure?

 

[bruno3047]

There is about 60-70 lbs of live rock

This was a very interesting read, I was surprised how much detritus was in the rocks when did a water change last night. Figured I'd do a bunch of water changes over the next couple weeks before I try and put anything back in.

I would hit that sandbed a little bit too, if I was you. If you have a sandbed.

 

[DavidinGA]

Was the sandbed disturbed before everything started dying?

 

[Tamberav]

Need more information.

When were the fish last seen acting normal? Eating and swimming normal?

Any unusual behavior? Hiding? Stress colors? Reduced feeding? Heavy breathing?

When was the last time something wet was added? Fish? Inverts? Coral? Algae? Cuc?

What do you dose? Carbon dosing? Other additives?

Any recent maintenance? Water changes? Filter changes? Removing debris?

Any new equipment? Power heads? Sump? Etc?

Do you use a skimmer?

Health of inverts? Any coral, cuc?, or anemone show stress?

Any potential power outage? You may not know if it came back on but stove clock or something may be off

Any potential foreign contamination? Fabreezez, window cleaner, pesticide spray outside and a open window, incense, etc