Lost 3 Hardy Fish In The Last Week!

[ey2006]

I have lost 3 fish in the last week - 2 zebra danios and a platty. I've had these fish for almost a year now.

With the platty, I saw the dead body floating in the tank, while the 2 danios were being eaten by an adult Bristlenose. I couldn't tell if the danio was still alive when the BN ate it. Also, one of the bronze corys looked like it had been attacked and was struggling, I took him out and moved him to another tank when I noticed this, the bronze cory is doing fine now.

other fish in the 450L tank include:

clown loaches
yoyo loaches
cardinal tetras
neon tetras
rummynose tetras
corydora

tank has been established and running for 8 months.

water conditions are fine and stable;

ph 6.6
Nitrite 0
Ammonia 0
Nitrate 15

I also noticed one of my rummynoses (I have 15 in total) completely losing one of its eyes. Do you know what may have caused it to lost its eye? It's head is still 'red' and looks healthy and is swimming with the group, but this is starting to cause some concern for me - I'd like to know if there is a fish (BN or loach) doing all this damage.

I can't tell what is killing these fish, whether it is some unknown disease in the tank, the BN or the loaches?

Prior to this I haven't had any dead fish in a while, so I would like to know what is causing these deaths.

Any suggestions would be appreciated.

 

[WILDER]

I would look at the bn, with one of the fish having an eye missing he could of sucked it out.
Plus you have seen him nibbling on fish.
How big is the bn compared to the fish you have lost.

 

[ey2006]

Wilder,

Thanks for the reply.

I have 4 BNs in the tank, 2 adults (1 male and 1 female) and 2 juveniles.

The 2 adults are about 4.5" and the juveniles are about 1.5".

If I do return the BN to the LFS, would I be able to get some store credit?

 

[WILDER]

Depends every store different but they you should do, but they might not give you the full value of the fish.