Why did my fish die in quarantine?

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BilboB

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This used to happen to me during the winter. I would wake up and several fish dead overnight with no signs of illness. It seems excessive CO2 in water was the cause. During cold months no open windows or doors so it builds up. I placed an air pump outside a window and ran a long airline hose to the tank for a few hours a day.
This stopped the mystery deaths for me.
That's interesting, but did the pH go down? CO2 dissolved in water lowers the pH.
 
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BilboB

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I don’t think this is water quality issue (for sure not nitrate) and it isn’t anything dietary.

The description sounds like Amyloodinium, velvet. The early symptoms of that are easily missed.

It isn’t a good idea to hold fish in a QT under purely observational management.

I just updated our quarantine protocol:
Fish can die from velvet without having patches of powdery sugar?

One thing I've learned from having QTs is that I really need them cycled - it's a pain to have to do big water changes every 2-3 days to avoid ammonia build-up. I'm going to have to treat a whole bunch of Matrix for future quarantining.
 

Jay Hemdal

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Fish can die from velvet without having patches of powdery sugar?

One thing I've learned from having QTs is that I really need them cycled - it's a pain to have to do big water changes every 2-3 days to avoid ammonia build-up. I'm going to have to treat a whole bunch of Matrix for future quarantining.

Yes, the powder sugar look refers to freshwater velvet. Marine velvet doesn’t show that…
 
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BilboB

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For what it's worth, the lawnmower blenny is still alive. Are blennies more resistant to velvet or poor water parameters than tangs?
 

Marine Betta

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For what it's worth, the lawnmower blenny is still alive. Are blennies more resistant to velvet or poor water parameters than tangs?
This does sound like velvet. I wouldn’t say they are more resistant to velvet. I’ve seen almost every fish get velvet. A velvet outbreak won’t always kill every fish in the tank. Are blennies more resistant to sub par water parameters? Maybe…but most fish can tolerate inadequate water parameters to a certain degree. Some are more sensitive than others though. If you haven’t already, I would begin the qt protocol provided by Jay.
 

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3 fish, 2 of them tangs in an un-cycled, unmedicated tank is a big risk.

The tangs are going to be so stressed their immune systems weaken. Anything goes wrong like short spike in ammonia or other minor water quality issue it will wipe them out. Could be why the blend made it.

In the future you may want to look at your quarantine process and equipment to minimize the risks. Relying on water changes is extremely difficult to balance even for the most experienced aquarist. IMO it’s better/easier to have a well cycled system as a starting point.
 
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3 fish, 2 of them tangs in an un-cycled, unmedicated tank is a big risk.

The tangs are going to be so stressed their immune systems weaken. Anything goes wrong like short spike in ammonia or other minor water quality issue it will wipe them out. Could be why the blend made it.

In the future you may want to look at your quarantine process and equipment to minimize the risks. Relying on water changes is extremely difficult to balance even for the most experienced aquarist. IMO it’s better/easier to have a well cycled system as a starting point.
The tank has 2 grapefruit-sized pieces of live rock from my LFS, so the tank should've been able to handle the ammonia even if I didn't cycle the tank ahead of time. In fact, the API ammonia test was near-zero for 5 days straight when the tangs died, so I didn't do any water changes. Maybe it was velvet.

In the future, I'll treat everything with copper using Jay's method. I'll replace the 2 live rocks with multiple bags of Matrix which I'm currently seeding in my DT. Hopefully they'll be sufficient to keep the ammonia down since I can't use live rock or calcareous sand.
 

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Fish can die from velvet without having patches of powdery sugar?

One thing I've learned from having QTs is that I really need them cycled - it's a pain to have to do big water changes every 2-3 days to avoid ammonia build-up. I'm going to have to treat a whole bunch of Matrix for future quarantining.

Yes the issue with velvet. And the myth that I spread, especially on FB is the powder sugar look. In reality it’s ich most of the time I see posts on FB.

It’s why the idea to get fish in copper as soon as possible is the best method. It’s what I started doing and the amount of dead fish I have on my hands now is zero! I have had cases of internal uronema, but that is just a ticking time bomb that you can’t predict sadly.
 

Marine Betta

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Yes, the powder sugar look refers to freshwater velvet. Marine velvet doesn’t show that…
Humblefish says marine velvet shows up at lots of tiny white dots

Velvet may appear as dusting, but that’s usually ich. More often than not, the fish will not any show visual signs of disease on the fish. Instead, there will be behavioral changes such as rapid breathing, swimming into the powerhead, etc. Death often occurs within 48 hours. Velvet often attacks the gills first and kills before visual symptoms can present themselves. This is why it’s important to treat with copper as soon as possible.
 

Jay Hemdal

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For what it's worth, the lawnmower blenny is still alive. Are blennies more resistant to velvet or poor water parameters than tangs?

Yes for both cases. For some reason, when we see epizootics (widespread infectious disease in tanks) blennies and gobies are often the last to die, but they are not immune.
 

W31Olds

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Could it be that most Blennies and Gobies are not active swimmers like Tangs and can survive longer because they don't need as much oxygen?
 

sgdnycct

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3 fish, 2 of them tangs in an un-cycled, unmedicated tank is a big risk.

The tangs are going to be so stressed their immune systems weaken. Anything goes wrong like short spike in ammonia or other minor water quality issue it will wipe them out. Could be why the blend made it.

In the future you may want to look at your quarantine process and equipment to minimize the risks. Relying on water changes is extremely difficult to balance even for the most experienced aquarist. IMO it’s better/easier to have a well cycled system as a starting point.
The tank has 2 grapefruit-sized pieces of live rock from my LFS, so the tank should've been able to handle the ammonia even if I didn't cycle the tank ahead of time. In fact, the API ammonia test was near-zero for 5 days straight when the tangs died, so I didn't do any water changes. Maybe it was velvet.

In the future, I'll treat everything with copper using Jay's method. I'll replace the 2 live rocks with multiple bags of Matrix which I'm currently seeding in my DT. Hopefully they'll be sufficient to keep the ammonia down since I can't use live rock or calcareous sand.
Live rock can help speed up the cycle. With enough relative to volume it could be almost instant. However that depends on the quality of the rock. You had recently seen ammonia in the tank which indicates the tank hadn’t balanced out. When you think that generally we assume a tank isn’t mature until about a year of stable parameters, any QT is going to easily get out of balance. And not just chemistry. What about temp? Was that stable?

Regardless I don think that’s the key point I was trying to make. A QT is unstable and highly stressful for the animas. No sand, few hiding spots, etc. you had two tangs in there. 20 gallons for 1 tang is already too small. The Kole may have been carrying Velvet but its immune system was fighting it. Then it gets stressed again coming from LFS to QT. Then it’s in a small tank with a competitor (YT). The yellow came with no previous exposure to velvet plus also finds its immune system compromised due to shipping and environment. IMO we just don’t focus enough on the stress levels these fish are under and how weak they get due to this. These two fish didn’t have the ability to fight off a disease, add the lack of medication to help them and they quickly succumbed.

I’m sorry for your loss and it’s good you’re asking questions. Hopefully it will go better next time!
 

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In the future, I'll treat everything with copper using Jay's method. I'll replace the 2 live rocks with multiple bags of Matrix which I'm currently seeding in my DT. Hopefully they'll be sufficient to keep the ammonia down since I can't use live rock or calcareous sand.
I try to keep a 6" air powered sponge filter in the sump of my main tank. Keep it running and seeded makes a great bio-filter for a quarantine tank. The sponges are cheap on amazo.n and can be tossed after every use.
 
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Paul B

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Yeah, I probably should have fed them nori instead, or mainly nori with some mysis.
I have no idea why your fish died and I won't even guess but I will say there is a reason I am 100% against quarantine and medications mainly for this reason.

But besides that. Not eating nori will not kill tangs. My tangs live at least 10 years and have never seen nori or any other seaweeds although I am a Diver and do see them eating it on the reefs. Apparently, they don't need it to stay healthy but it won't hurt.



 

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