Why Is Fish Spinning When Swimming

[xllxSBxllx]

Got 24" tank with 1 molly, 2 gouramis, 1 siamese fighter, 1 angel, 1 catfish, 3 red eye tetras and 2 black neons.
All the parameters are right but one of the neons has started to spin whilst swimming could anyone suggest a reason for it? and will it die? please HELP!

 

[Chrispixx]

This should be in the TFE forum maybe a mod will move it for more responses

Is the color faded on the neon? faded color goes with neon tetra disease (NTD). is the tank cycled? how long has it been up and running? Neons should only be added to a well established tank, as they are sensitive to the water parameters.
Do you have a test kit? or know the water stats.
I have sworn off keeping neons because of the problems they have (NTD) i have some now but when they die (of old age or whatever) that will be it with neons for me.

 

[rdd1952]

I'm going to move this to the emergency section but it sounds like a swim bladder or constipation. Try feeding him a cooked pea with the hull removed. Just mush it up good. You can do several and feed the whole tank to make sure he gets some. Usually, that will cure constipation. If it is swim bladder, that's usually not a good sign.