My Neon Tetras Tail Is Pointing Down Sorta Is It Bad

[betta989]

i looked into my tank and i saw his tail was pointed down lil and he started to float down is it injured?

 

[WILDER]

Size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.

What do you feed the fish.

Swim bladder can look like the tail is weighing them down in the water.
Does he look bloated.
Can he maintain his balance in the water.
is the red stripe still vibrant red and not look bleached out.
Has any other fish been attacking him.

Swim bladder can be caused by bad water quality, injury, birth defect, unstable diet, to many dried foods, parasites internal, bacterial infection of the swim bladder, unstable temp.