I have a 5 gallon aquarium divided, no filter but I do have a heater in it--water stays about 78 degrees and it was just changed out about 3-4 days ago. My problem is, one of my female bettas was found floating lying on her side on top of water tonight, I touched her and she swammed away kind of leaning to one side, but seemed to have a problem going underwater very much. I kind of pushed her under the water a little and immediately she rose back up and kind of float/swimmed around again. What can I do, what causes this and is this a fatal problem??? Do to some of my other female bettas dying about 6 months ago, my 6 yr. old girl had a hard time dealing with there deaths which we are still puzzled what happened to them. She probably will give me hell if this girl dies, it's either hers (Rachelles) or my other 3 yr. daughter (Gabrielles) fish, either way it'll be a rough time for them both. If anyone has a suggestion it'd be appreciated.