White edge tail fins on new discus

[phillyko]

Hi
so I bought these 5 discus just a few days ago and they seem to have a slight white edging on their fins. I feel like it could be fin rot but the tank parameters are perfect and water quality is too. could it possibly be just from stress? They're very active and have a great appetite still as well and it only seems to effect the tail fins.
Thanks!

 

[phillyko]

here is a pic of one

 

[Brookster123]

Insert all the details of your tank here please.