2 new danios dead on same day after 2 weeks... wat

[bloodlucky]

40 gallon, fully cycled tank thats been running over a year

1 baby angelfish (bought a few days apart from day I bought the two new danios)
3 zebra danio (now that the two new ones have died)
5 gold barbs
6 neons

Not really sure why this happened but last night I saw both the new danios very inactive and hanging around the surface, one was actually floating on the surface but I assumed it was nothing...

Not sure what the problem is and why it happened so suddenly and on the same day coincidentally. The baby angel is too small to have killed it and I haven't seen any prior aggression at all between the baby angel and the other fish, danios included.

Params are fine, fed twice a day and the danios are always the first to find the food

But the danio bodies were both mutilated and eyes were eaten out, so clearly something ate it after it died, probably the angel

 

[cfosgate]

What are the water params? How often do you do water changes and how much do you change?

 

[bloodlucky]

What are the water params? How often do you do water changes and how much do you change?

Found my kit ammonia and nitrite is 0 but I don't have a nitrate kit, but I can assume its at a safe level since no other fish are unhealthy

I do a weekly water change but now its starting to shift towards 2-3 times a week, I guess paranoia comes into play lol

 

[cfosgate]

Nitrates could be really high and the new fish may not have adjusted well whereas the existing fish became used to the nitrate load over time. You're okay with WCs so I can't come up with any other theory.

Anyone else? Ideas?

 

[bloodlucky]

Nitrates could be really high and the new fish may not have adjusted well whereas the existing fish became used to the nitrate load over time. You're okay with WCs so I can't come up with any other theory.

Anyone else? Ideas?

Been thinking the same thing.

 

[bloodlucky]

update

Okay this is getting really weird my danio that I had from a year ago just died last night and he looked inactive the day before like the new danios did...

 

[Coursair]

The Barbs perhaps ?
Or a parasite ?

 

[bloodlucky]

The Barbs perhaps ?
Or a parasite ?

Barbs have been in the tank since last May and they're really mellow. Maybe a parasite but their stomachs don't seem to cave in like my last parasite incident

 

[bloodlucky]

The rest seem fine. I'm assuming extreme bad luck