Sudden death fish

[Dave1987]

Hey guys ive got a mystery on my hands.

Last night my yellow tang started breathing heavy and a few hours later it died. At the same time my 2 firefish did the same thing. All other fish were and still are totally fine. No new fish were introduced in the last 1,5 year.

Tested all water parameters incl amonia, no2, ph, iron. nothing came up. I know my tang is verry sensitive to iron and seen symptoms like this before when dosing.

I did clean my skimmer thouroughly and my maxspects. Thats the only different thing that happened yesterday.

Its a total mystery for me what happened here. It was like they suffocated. Did the improved skimming do anything? Because it was really really dirty.

Hope anyone can shed some light on this. Corals are fine btw.

 

[fishguy242]

hi,what size tank,what did you use to clean equip?

 

[Dave1987]

90g. Used a fresh sponge and vinigar Like many times before. Rinsed well with fresh water before putting everything back together.

Emediatly placed 500gr carbon. But that didbt help exept tic of my acros.

 

[DED65]

What kind of sponge did you use? I don't know if that could have had any to do with the fish deaths, but a lot of sponges contain chemicals and detergents. I only use brushes and Mr Clean original scrubbers to clean anything in my tanks.

 

[Dave1987]

No detergent in these sponges. Used them for years.

And why these specific fish only.

 

[fishguy242]

what other fish are ok? was tank completely shut down while cleaning? if so how long?can you post pic of tank?

 

[Dave1987]

No not shut down.

Clown fishes, copperband, sixline, mandarin. Snails also fine.

I just cant get my head arround it. Im thinking something that the skimmer changed when running again at full power. Some kind of reaction. Or something like iron.

All corals are fine. There isnt anything out of the ordanary today. Except 3 dead fish yesterday.

 

[Redfoxtang]

Sixlines can be pretty aggressive maybe he could be the culprit?

 

[Dave1987]

Not agressive here. And killing a full grown tang, and 2 firefish at the same time.. without me seeing? Hes a good boy.

They were gasping for air.

 

[Quietman]

Could O2 have dropped or CO2 spiked? Aeration - maybe bad timing on cleaning at a high CO2 spike? I'm reaching a bit.

 

[cmoore806]

You didn't mention salinity or top off situation...Im assuming its okay but just to be thorough what's the salinity story?

 

[fishguy242]

??? rinse carbon before adding?? stumped at this point..following

 

[davidcalgary29]

Did you do or attempt necropsies on them? Sorry for your loss.

 

[Tired]

Has anyone sprayed anything near the tank, or lit any candles? Air freshener, cleaners, anything?

 

[Jay Hemdal Verified Community Expert]

This is definitely an odd case. Common water quality issues would show up in the inverts before the fish. Diseases would center on the fish, but wouldn’t be so selective.
Did the 3 fish die with their mouths agape?
Jay

 

[JumboShrimp]

Just a thought: Were you possibly providing just enough oxygen in that tank for the fish to survive, but when you took the skimmer off-line the loss of aeration from the skimmer was the tipping point, suffocating them before you noticed what was happening?