sudden death

[junolake]

trying to figure out cause of death. Fish tank is 150 gallon, heavily planted , showing 0 nitrates, 0 nitrite, 7.0 ph been running for 5 years. Stocked with all adults 6 angels fish, 2 keyholes, 7 brilliant rasboras, 2 Bolivian, 5 hatchets, 7 cardinals , 7 rummynose, 3 sae, and assorted corydoras.

Decided to add fish without quarantine ( dumb), added 6 additional rummynose, 6 additional cardinals and 4 lemon tetras and 5 diamond tetras. Two weeks later all cardinals, most rummynose (2 left) and all lemon tetras are dead . Remaining fish including diamond tetras are alive and appear fine. All remaining fish are eating and appear healthy,

I cant figure out what killed both the new and existing cardinals , rummy nose and lemon tetras but left remaining fish OK(for now) . Tested water everything is stable , I don't know what I'm supposed to treat. Any suggestions will be appreciated.

 

[MacZ]

I'm sorry to hear, but finding out in hindsight what killed them is almost impossible to find out.

But I give you two possible factors: If the tetras were too small the angelfish might have gone for some snacks. And as you said you didn't quarantine.

That's all one can say with the info you give. But really finding out is impossible without taking a look at a dead specimen and disecting it.

 

[junolake]

I'm sorry to hear, but finding out in hindsight what killed them is almost impossible to find out.

But I give you two possible factors: If the tetras were too small the angelfish might have gone for some snacks. And as you said you didn't quarantine.

That's all one can say with the info you give. But really finding out is impossible without taking a look at a dead specimen and disecting it.

 

[junolake]

Thanks, I've had the cardinals and rummynose for several years never a problem sad to see them go. I will wait several months and quarantine before adding new cardinals and rummynose.