sudden death on bichirs

[andre07]

I just lost 2 bichirs in one day. Both of them showed the same symptoms. Before they passed away, they were trying to swim,but movement is erratic and they end up upside down at the bottom of the tank.
Anyone familiar with this case?

 

[Dr.B]

How long has your tank been running? Tank mates? Water parameters?

 

[andre07]

How long has your tank been running? Tank mates? Water parameters?

The tank is well established for 2 years now. Mostly bichirs, with an arowana, a datnoid, a paratilapia and a clown loach.
Ph 8.4, amonnia 0ppm, nitrate 0ppm nitrite 0ppm

 

[Dr.B]

Any recent changes, additions, or abnormalities (in the tank and fish leading up to the deaths)?

 

[andre07]

Any recent changes, additions, or abnormalities (in the tank and fish leading up to the deaths)?

Haven't change or add anything,other than fed them something new, I gave them some of the hikari sinking cichlid gold.

 

[Dr.B]

I usually see this kind of behavior when there is something wrong with the parameters. Especially with ammonia poisoning, but seeing as how your params seem fine I don't know. What species and how large are we talking?

 

[andre07]

I usually see this kind of behavior when there is something wrong with the parameters. Especially with ammonia poisoning, but seeing as how your params seem fine I don't know. What species and how large are we talking?

If the water parameters are off, would the arowana and the cichlids will be the first to get stressed?
Anyway one of the bichirs that is belly up managed to survive, I transferred it last night to a hospital tank.
The lapradei was 14inches, arowana is 20 inches, midnight cichlid is full grown, other bichirs are between 10-20 inches.

 

[Dr.B]

Do you have a picture of the lap?

 

[jaws7777]

Dr b pretty much has you covered but if the nitrate was 0 that would indicate somethings off....should always register some nitrate unless you did 100% wc before testing

 

[andre07]

Dr b pretty much has you covered but if the nitrate was 0 that would indicate somethings off....should always register some nitrate unless you did 100% wc before testing

1
No I didn't do any wc prior to using the api test kit.
Well the color is between 0ppm and 5ppm. Maybe kit is going bad? Nitrate reads almost the same just like on my heavily planted discus tank.