11 dead cardinal tetras in last few hours

[Bigebee]

Just got home and noticed I have 11 of 13 dead cardinal tetras floating/tangled in the plants. All of my discus look great. All of my cory cats look great. Water temp is at 85F and everything appears normal. Did a water test and have 0,0,5 (NH3, nitrite, nitrate). Did a 25% water change this morning that appeared to go fine as well. Nothing else looks out of place other than a lot of brown algae. I'm getting ready to do another water change just in case, but thoughts?

 

[Slappy*McFish]

How were they acclimated and where did you purchase them?

 

[Bigebee]

I've had them about 2 months. From Fosters and Smith They have been doing great.

 

[Slappy*McFish]

I don't know, that's strange. Neon Tetra Disease perhaps?

 

[rufioman]

Did they all drink the kool-aid?

 

[jpappy789]

Anything added/removed recently? Has your normal routine changed? Nothing out of the ordinary in the past week or so?

 

[Bigebee]

Nothing has changed at all in the routine. The last "major" change was a filter cleaning with my fluvall 305 but I rinsed sponges in tank water and made sure to not disturb the bacteria too much. Again, the water parameters test good. Another thing, maybe coincidence, most of the 11 were found in entangled in the same plastic fern plant in the tank. Maybe due to currents or something but almost seems like it all happened at once. They were good when we left the house and 3 hours later came home to find them dead.

 

[iheartbettas]

sorry for your loss. That's pretty tragic. I just can't imagine that fish would get tangled in some kind of plastic plant. All your water parameters are good. i've no idea.

 

[Danny-O]

Maybe the 85 degrees is a contributing factor. I know discus like it warm, and the tetra should be able to adapt. But if something does go awry with the tetras, the higher temp might make it all happen faster.

 

[discuspaul]

That is a real mystery shocker - never heard anything like it.

You've had those tetras in with the discus @ 85F for 2 months without a problem, all your parameters have been well maintained (presumably for the discus' sake if nothing else),you haven't made any major changes of any kind, and all of a sudden, in just 3 hours' time, you lose 11 of 13 fish that have been good for 2 months !!
Real odd - it can't be the temp, nor that fern-type plastic plant - could it possibly be something as far-fetched as some new food you introduced just before leaving the house ? Perhaps some minor electrical malfunction that occured, harming the tetras but not all the larger fish ?
This is stretching things, but what else could possibly come to mind - just to you - cause you were the only one there when it occured. Think about it some more, if you care to.
Sorry for that kind of loss - it sucks.