HELP!! Why do my fish get so stressed that they die when I use the quarantine tank?? (I know, it sounds bad)

This is the second time that a fish of mine almost died when I put her in a separate tank. I think she has a disease or a virus like hemorrhagic septicemia, and I don't want her infecting other fish. All I have is a standard fish bowl, so I fill it with the usual gravel, take some water from her original tank plus some fresh, treated water, leave it overnight to make sure the treating gets all around in the water and the tank and fresh water mix, and put her in. As soon as she got in there, she began acting in almost the same as the last fish that I put in there. Her illness symptoms are bulging eyes, fast breathing, slower reaction time, and she's not eating. A friend mentioned that her stomach looks a little bigger than the other tetras like she is bloated. When I put her in the bowl, she settled to the bottom, became still, and her breathing got much slower like she was dying. I had a pregnant molly that I wanted to move so she can have babies, since I didn't have a breeder box. She went between sudden bursts of swimming around really fast and then stopping and going very still before giving birth to dead half-done looking babies and dying an hour later (It was really sad and I still feel really bad about doing that). As soon as I saw my Glofish tetra settling to the bottom, I immediately took her out and put her back in the tank with the others, afraid that she would die. Once I put her back, she went back to being her sickly Glofish self.
I don't understand, though! I don't want her infecting the other fish, but the stress from being put in the bowl will definitely kill her. What am I doing wrong??

 

Do you have anything aerating the bowl? Did you notice her "gasping" near the surface at all?

 

Possibly because it has such a small water volume plus the fact of the fish being stressed from a move to an unfamiliar environment.

 

Do you have anything aerating the bowl? Did you notice her "gasping" near the surface at all?

I don't have an aeration system in it, but I didn't see her gasping at the top. All she did was settle as the bottom and her breathing slowed down really fast. I have a heater that I can put in it if it's too much of a temperature difference, but not a filter.

Possibly because it has such a small water volume plus the fact of the fish being stressed from a move to an unfamiliar environment.

Is there anything I can do to help her be less stressed? I tried giving her some food, but she didn't even look at it. And I put the bowl next to the tank so she can see that she didn't go very far.

 

Tetras are a schooling fish so they get stressed when alone. It also sounds like they went into shock when you put them in the bowl. An aerator in an absolute MUST, so is a heater.

 

Well its not a matter of it looking over and saying hey im close to home, it still is in an unfamiliar environment- not as much space, different layout, and such, and no conspecifics. A bowl is really unsuitible for a QT tank anyway. Really all i can suggest for now is water changes. Lots of them. And a larger tank for QT, with hides and such.

 

Did you acclimate her? Temp. or pH differences could be it if you did not. I would not move one fish directly into another tank without acclimation. Also, if you are doing a QT tank, you don't need tank water. You need fresh dechlorinated water at a temp that is what she's used to, that is healthy. All you need is a plastic bin with a cover, and a sponge filter. You can get a 10 gallon one or 10-20 gallon one for 5-6 dollars on Amazon. The sponge filter will act as an aerator also. You can put gravel, fake plants, a hide, etc. The key is the sponge filter and heater. If you think they are sick, there is no wisdom in waiting a day for the water to settle.