Saltwater Fish Died in Quarantine Tank -- Diagnosis Help

Hello,

Sadly, two of my fish a yellow belly damsel and a Ruby Head Fairy Wrasse in my quarantine tank have just died (or close to the death) when I awoke in the morning. The odd thing is that all my parameters are fine.
Here are my parameters:
Salinity: 1.025
PH: 7.8
Nitrates: 5.0
Nitrites: 0
Ammonia: 0.5 (began treating the tank with Prime just in case)
Temperature: 76.1

Thus, I am a bit confused. I bought them from a reputable Local Fish Store. They stated that they've been treating them with medication for 2 weeks with no problems. I've only had them for about 4 days. The only thing that I can think of is that maybe the water oxygenated enough but I have Amazon.com so the water should be aerated. The reason why I say that there might be not enough oxygen is because they keeping opening and closing their mouths. Also, they look a bit paler as well.


Based on my description, could anyone help me diagnosis the issue? I want to try to learn from this experience and avoid anything like this happening again.

Thank you!

 

Ammonia spiked before or after they died? Most likely answer: Ammonia Poisoning.

 

GoldenToaster3300 is correct, you don't have a cycled tank so they died of ammonia poisoning. Are you aware of what a tank cycle is and how to do it? The nitrogen cycle is one of the most important parts of owning fish. Fishlore has some good articles on it and they're super easy to find on the internet. Learning from this is good, it's really easy to make these mistakes if you're beginning.

 

hmm...aren't you not supposed to cycle a quarantine tank though? From what I read you are not supposed due to the medications you put in the water. Instead, you are supposed to use ammonia detoxifiers. But ammonia can spike and go down within a day like that because the ammonia is 0.5 right now?

 

hmm...aren't you not supposed to cycle a quarantine tank though? From what I read you are not supposed due to the medications you put in the water. Instead, you are supposed to use ammonia detoxifiers. But ammonia can spike and go down within a day like that because the ammonia is 0.5 right now.

I think it depends on what you're medicating, but the fish can't go long term in a tank with ammonia in it to my knowledge. I could be wrong, but the symptoms described also sound exactly like ammonia poisoning to me.

 

I think it depends on what you're medicating, but the fish can't go long term in a tank with ammonia in it to my knowledge. I could be wrong, but the symptoms described also sound exactly like ammonia poisoning to me.

Ok, I guess I'm going to just redo everything start from scratch. I'll wait until it's fully cycled.
Also, can ammonia spike then lower at night? Is that something that is really possible?

 

Quarentine tanks need at least a cycled filter. Keeping one in a sump or established tank to keep the bacteria fed is the easiest way to always have one around without keeping the tank set up permanently.

Taking a piece of live rock or some sand out of a cycled tank would help things now.

 

Quarentine tanks need at least a cycled filter. Keeping one in a sump or established tank to keep the bacteria fed is the easiest way to always have one around without keeping the tank set up permanently.

Taking a piece of live rock or some sand out of a cycled tank would help things now.

Good news though, my sick fish has pulled through and is eating like a champ. Super happy about this development. I have to say the API stress coat works wonders.