Dead Guppy, Red Spot

[TheFishTanksInTheBasement]

We had a guppy die last night. We bought her a few nights ago from petco and she seemed perfectly fine. She was mingling with the other guppies and what not so there wasn't any aggression in the tank as far as I know. I got a decent picture, maybe you guys can figure out what happened.

 

[Daddynev]

Hi I had a similar red spot on one of my guppies about a year ago soon after buying it. Someone on this forum suggested it was ammonia/nitrite burns and suggested a large water change and some salt. It cured it very quickly. Sorry to see your guppy die .