Massive fish die off

[Moldoc]

I got a bunch of fish that are starting to die off rapidly. I have lost 10 fish since I got them and put them in QT 4 days ago. All of the fish that have died so far have had pink fleshy colored patches on their bodies and some of the live chromis have it right now also. It almost looks like the scales have peeled off in those areas. Any ideas of what is going on and what I can do to save what I have left?

[odysseysteve]

Anyone intending to assist you with a diagnosis would need to know stuff like: size of tank you have, filtration type, lighting type, tank age, and all water parameters that you can test.

[Moldoc]

The tank is a 24 gallon aquapod set up as a QT. It has a backpack skimmer on it and metal halides but I'm not really running the lights right now. Nitrites are at 0, Nitrates are 10, maybe a little more but definitely less than 20, Ammonia is at .25. I think this may be from all the dying fish... Out of the 12 chromis, only 5 are still alive and one has that reddened skin and is not really swimming anymore... I am losing about 2-3 fish every 24 hours. The firefish, mandarin and powder blue seem to be doing just fine. But the 6 line and chromis are croaking left and right... Help please!

[99sf]

I recommend immediately doing water changes. Sounds like you have a huge number of fish in a tiny tank. Bioload is probably way too high. Remove the dead fish... you are going through a major nitrogen cycle.

[goody]

Hey Enoch, I had a problem where 1 of my Chromis would disappearing every day. This happened to me twice. Are yours disappearing or are they dying and you see the bodies? I was told Chromis can pick on each other, maybe this is happening. Where did you buy them? Chris at Lotsa Fishes is a great vendor and he's doing a run soon.

[impreza619]

Enoch, chromis sometimes pick each other off or just die off due to a bad batch. I started with 12 chromis 6 months ago and during the first couple months they started to disappear. Now I have 6 months later I have 6 left and no more have disappeared. The red blotches and missing scales are wounds inflicted towards each other.

I would do a water change or use some tank water from your larger tank. That way the water you would be adding would help to stabilize the tank. I would add come Cupramine to the qt after adding tank water just to kill any organisms added from the used tank water.

Good luck! Let me know if you have any questions via pm.

[Moldoc]

Thanks for all the help guys! Did a 20% change, then lost one more... The red marks do look like wounds. I don't see them fighting though. They have been schooling since I got them. That would explain why only those fish are dying and the others seem to be getting stronger each day in the same tank.