Redhead tetra might be sick

[Kaycool123p]

Hello I just got these redhead tetras today but I noticed somethings about them that are weird there's on that can swim and there's one that's has a bend back and the others look like they

can't swim that well either but here's some videos if yall could tell me what's wrong.

 

[Dephea]

Rummy nose tetras are very sensitive. Did you acclimatise them slowly? How many did you get? How long is your tank running for? Is it cycled? What other fish do you have? What are your water parameters?