Mass deaths overnight.

[Phill79]

Hi, I'm new to the forum so hope I've posted this in the right place.

I fed my fish on Wednesday night and all was fine, all the fish fed well, there was no sign of illness among them. On Thursday morning i switched the lights on and looked in the tank and noticed my yellow tang, coral beauty and three anthias were missing, i noticed the tang dead on the sand, 1 antias dead on a rock, another anthers being eaten by the cleaner shrimp and one missing along with the coral beauty.
My clown fish was gasping for air and wobbling when swimming, My two blue/green chromis, cleaner wrasse, orchid dottyback were all fine as far as i could tell. Just before I turned the lights out in the evening i saw the final anthias wedged in a rock, alive but gasping for air but i couldn't get to him. This morning he, the clown fish are both fine and have eaten the food offered.

I tested the water parameters and all were normal, nitrates and ammonia were slightly up but i assume this due to dead fish in the water. I took some water to my local fish shop and they came back the same as mine.
All the coral, snails, crabs and shrimp are all also fine, I would have thought they would be first to suffer if water problem.
All the pumps and equipment is working.

Any ideas what may have caused this as I'm at complete and utter loss. not to mention devastated.

Thanks in advance.
Phill

 

[Sapelo]

Before we can even attempt to help you, we need specifics on your system.

What size tank do you have and what is your filtration?
How long has your tank been set up and what cycling process did you use?
What (in numbers) are your parameters?
How long have you had your fish and in what order did you add them?
Did you quarantine your fish and if so what method/methods did you use? I'm wondering specifically if you treated them for anything?
When you say pumps and equipment are working, what specifically do you mean?

Honestly sounds like your tank wasnt cycled but need way more information to make that leap...

 

[Phill79]

Before we can even attempt to help you, we need specifics on your system.

What size tank do you have and what is your filtration? Tank Size is 250ltr Red sea max
How long has your tank been set up and what cycling process did you use?The tank has been up and running 4yrs, re the cycling I followed the advice of the las at the time as new to marines, I added the water and live rock, a selection of shrimp, crabs etc after a week and first fish after 8 weeks when all the levels were steady
What (in numbers) are your parameters? PH 8.1 KH 8 Nitrite 0 Ammonia 0, was less than 0.25 yesterday, Nitrate <1 was 10 yesterday
How long have you had your fish and in what order did you add them?None recently, The clown was added first 6-8weeks after the tank was set up, the coral beauty, tang a month after that, the chromic and anthias middle of last year and the dotty back at xmas.
Did you quarantine your fish and if so what method/methods did you use? I'm wondering specifically if you treated them for anything?I didn't quarantine, they have never been treated for anything.
When you say pumps and equipment are working, what specifically do you mean?
The stock pumps that came with the tank at the time.
Honestly sounds like your tank wasnt cycled but need way more information to make that leap...

 

[Dmorty217]

With the mass deaths I would lean towards velvet and the heavy breathing/gasping. What is the last WET thing added to your tank?

 

[dendrite]

The tank has been set up and running for four years, the last fish added was three months ago and all were happy and healthy until the rapid and catastrophic die off. Any disease or parasite would first make an appearance then multiply and kill. Really sounds like hypoxia or some kind of liquid or aerosol poisoning. No expert in fish death just the human kind.

 

[Phill79]

With the mass deaths I would lean towards velvet and the heavy breathing/gasping. What is the last WET thing added to your tank?

The last fish added was the dottyback at xmas 2015.
Is that normal? as they have shown no signs of illness etc, and to happen within the space of 12hrs seems odd. The clown and remaining anthias are no longer gasping and seem normal that is what I'm finding difficult to understand.

 

[Deinonych]

My guess would be stray voltage or some sort of toxin if nothing has been added in 3 months.

 

[Dmorty217]

The last fish added was the dottyback at xmas 2015.
Is that normal? as they have shown no signs of illness etc, and to happen within the space of 12hrs seems odd. The clown and remaining anthias are no longer gasping and seem normal that is what I'm finding difficult to understand.

What about CUC or corals, shrimp? Any or all of those can harbor disease from their holding tanks

 

[Reefstarter2]

My guess is a bacterial bloom that used up all the available oxygen in the water

 

[vhuang168]

Did you move any rocks, stir up the sand etc? That could cause a spike in ammonia that would poison the fish, then your tank processed it through the night so you see low levels.

 

[Phill79]

My guess would be stray voltage or some sort of toxin if nothing has been added in 3 months.

Would that not affect the corals and cuc.

What about CUC or corals, shrimp? Any or all of those can harbor disease from their holding tanks

Nothing since the dotty an December..

My guess is a bacterial bloom that used up all the available oxygen in the water

Would there be any visible signs of that?

Did you move any rocks, stir up the sand etc? That could cause a spike in ammonia that would poison the fish, then your tank processed it through the night so you see low levels.

Not me but the clownfish did kick up a load of sand with his tail fin, he has done this since I got him so didn't think anything of it.

 

[Deinonych]

Would that not affect the corals and cuc.

Good point...likely yes. Other things that might cause mass fish deaths are disease vectors or low oxygen saturation. The fact that the fish with the higher metabolisms died might point to the latter as a cause. Low oxygen saturation could be caused by complete lack of flow, or a carbon source being introduced (bacterial bloom).

 

[Sk8r]

Toxin or low oxygen would be my suspicion. Stray voltage from cracked heater possibly. So sorry for this---I've had it happen when an air hose failed (freshwater.)

Have you used any scented candles, room fresheners, carpet fresheners, particularly cleaning products? These can cause troubles. Ditto children throwing battery-driven objects into tank.

 

[Phill79]

Toxin or low oxygen would be my suspicion. Stray voltage from cracked heater possibly. So sorry for this---I've had it happen when an air hose failed (freshwater.)

Have you used any scented candles, room fresheners, carpet fresheners, particularly cleaning products? These can cause troubles. Ditto children throwing battery-driven objects into tank.

Hi
We don't use anything like that in the room the tank is in, very cautious about things like that have read horror stories.

I do think it sounds like something toxic but it's the only affecting fish that I find odd and two who were ill and gasping are now fine.

 

[jbvdhp]

In my experience if it was a bacterial bloom, you usually see cloudy water. May not always be the case but maybe. If it were that then yes all the oxygen is used up. This is strange.

 

[bat21]

This is terrible. I really hope you can figure out what caused it. Do you have one of the pumps pointed at the top of the water? Do you run the skimmer? You seem like you know what you're doing, so I wonder how the oxygen could be depleted like that with no obvious equipment failure.

I have the RSM250 also. Definitely want to know what happened here in case it is something I need to worry about.

 

[Phill79]

I'm wondering now if it's possible that the clown fish has kicked up something from the sand that has caused the oxygen to deplete. There was no cloudy water.

This is terrible. I really hope you can figure out what caused it. Do you have one of the pumps pointed at the top of the water? Do you run the skimmer? You seem like you know what you're doing, so I wonder how the oxygen could be depleted like that with no obvious equipment failure.

I have the RSM250 also. Definitely want to know what happened here in case it is something I need to worry about.

The surface water is well agitated and the skimmer is always on.
I wouldn't worry about it being an rsm problem, I think I've been unlucky.

 

[ThRoewer]

Sounds like a toxin, either introduces with the food or released by something (invert or coral?) in the tank. Different fish families have different sensitivities, which would explain that not all fish are affected.

 

[jmm]

Fumes from cleaning products used on floor, bleach fumes from cleaning toilets (makes ammonia and bleach).

 

[krullshards]

I'm certainly no expert but I was going to ask if something could have been in the food like ThRoewer is suggesting. Were you feeding anything new? Do you enrich the food with VitaChem, Selcon, garlic anything that could have potentially become toxic?

Again, I'm not sure if any of that stuff even makes sense, but I figured I'd put it out there in case it helped.

Before getting into this hobby I never would have believed it was possible to get attached to a fish like one would to a dog or cat, but I have gotten attached to my fish and I hate it if a fish doesn't make it. I hope you figure out what happened, if only to prevent a recurrence.