In need of help. Glofish swimming with tail up somewhat and erratic circles.

[January1]

I have a 20 gallon filtered tank with a blue gourami, 3 glofish and 3 tetras.
I've had the tank for around seven months now.
Heated to 80 degrees.
Parameters this morning with API Freshwater kit: Ammonia:0.25 Nitrite:0 Nitrate:40 (performed 25% water change with vacuum).

One of my Glofish is swimming with his tail up a bit though he is not completely vertical, which any time I've seen that they usually became less mobile and died within the next 1-2 days, but it doesn't seem like he is exactly experiencing that because he's still eating, he still swims around, and this morning started going around in circles and acting a little erratic. He is bending a little like he is chasing his tail, or circling upside down and back. So something is obviously wrong but he doesn't look like he's *that* bad yet. He actually seemed a little worse yesterday. He was floating tail up more. I have suspected swim bladder but I'm really not familiar with that particular problem so I'm not sure. All of my other fish are acting fine and look fine. I am curious as to how I should treat this one fish since he's in a community tank, I do have equipment to set up another tank if he needs to be quarantined, but I'm concerned about the water because I've heard you should have a cycled tank to house sick fish. I do have API T.C tetracycline, melafix, quick cure and aquarium salt on hand, and I have tetra safe start and water conditioner. (Just listing everything I have on hand so it will be known in advance). I'm not even sure if he needs the medicine or a natural remedy. I know the most important thing is keeping the water clean but that's about all I know regarding this so any advice would be so appreciated.

 

[Gavinpop1235]

Goldfish are cold water fish they live in colder water 50 - 70 degrees and goldfish are not good community fish they can get sick from other fish they only get along with their own kind

 

[sinibotia]

Goldfish are cold water fish they live in colder water 50 - 70 degrees and goldfish are not good community fish they can get sick from other fish they only get along with their own kind

Glofish.... not goldfish.

January, first, are you sure your ammonia test is at .25? If so, that's a problem. Try looking at it in brigh light through the bottom, if it seems yellow that way you're probably fine. If it is actually .25, then that could be your problem. Even that much ammonia is dangerous.

However, 40 nitrate is REALLY high. You want to do water changes that will bring it down to below 10, and try to keep it below 20. I suspect that that alone might be the source of your difficulties.

Edit: Now that I think about, there are several different species marketed as glo-fish. I know one of them is zebra danios but I forget the others. In any case, 80 is pretty warm for all of the fish in your tank. I would bring it down to 76, especially if the glo-fish you have are zebra danios.

So slowly adjust the temp down and do water changes to drop the nitrates and see if that helps.