White Cloud Minnow Death

I woke up to a dead golden white cloud minnow who had shown no signs of illness before dying. My water parameters were perfect prior to him dying. After testing when I saw he died ammonia was at .25 probably due to his death in which I did I prompt water change. Nitrites were at 0ppm and nitrates we’re at 5ppm so I’m confused since this shows pretty good water parameters even after his death. I had been fighting ich earlier about 3 weeks ago but all signs of it have been gone for at least a week. Upon inspecting the dead fish (who was partially eaten) there was no white spots or any sign of illness whatsoever and none of my other fish show signs of illness. I’m wondering if the higher temp (86) due to me treating the tank caused him to die? There’s no medication in the water just raised temp but I did just give medicated food for parasites in case it was that which killed it. Can anyone explain why he died?

For reference this is what they look like, I personally can’t identify any signs of illness

 

86 is pretty darn high for white clouds.It could very well be your culprit.

 

86 is pretty darn high for white clouds.It could very well be your culprit.

Okay /: I lowered the temp thinking that could be it but I wanted to make sure the ich was gone and was told it was the best way to treat it

 

Okay /: I lowered the temp thinking that could be it but I wanted to make sure the ich was gone and was told it was the best way to treat it

Yeah I understand.Raising temp is common way to speed up ich life cycle.im not saying 100% that's what killed your wcmm tho.They can often take some less than ideal conditions and turn out fine

 

Probably temp esp if you raised it fairly fast. Also when you cool it down do it slowly.
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slowly is 1 or 2 degrees a day; though 2 degrees over 12 hours is probably fine.

 

Yeah I understand.Raising temp is common way to speed up ich life cycle.im not saying 100% that's what killed your wcmm tho.They can often take some less than ideal conditions and turn out fine

I’m assuming it was the temp because they all look okay with no signs of disease