Any ideas on what happened to this fish?

[Spacebug75]

So, my sister was given a betta fish last week. She really didn't have any idea how old he was or anything, but he seemed fine. She kept him in a one gallon bowl for a few days and he made a big bubble nest and ate well. She then moved him to her 10 gallon, cycled, filtered tank. It wasn't heated, but the water was not getting too cold. He was only in there a couple of days. She said last night he did this cough-like thing and looked like his color had faded a little, and then this morning he was dead.

Is there any way to tell what could have happened?

[tpocicat]

How cold is "not too cold"? Bettas are tropical fish so they need warm water. Does your sister have a temperature gauge? I'm not saying that was the problem, but that is the only thing I can think of from the information you gave us.

[Spacebug75]

low 70s. Not sure about her temp gauge, I'm just going by what she said. I know the fish should be kept at warmer temps, but I didn't think they'd die unless it was much colder.

[Spacebug75]

Well, the mystery seems to be solved. After talking to my niece, I learned that the fish was found at the intake valve of the filter, and it seems that the intake basket had been improperly assembled, so that the basket was actually placed inside the intake tube.

Sigh.