Is this a blue acara, hybrid or saum?

[affena]

I bought two blue acaras or so I thought, but at home I noticed that this one has a line at the tail fin. Can someone help me to identify this one?

Thank you!

 

[1 2many]

It looks like you have 2 juvenile Green Terrors.

 

[affena]

Sorry, I forgot to mention that It's the same fish in both pics. The other one I got is definitely blue acara.

 

[1 2many]

No problem. I would say the fish in the picture is a green terror/saum

 

[Deadeye]

Agree white suam green terror

 

[duanes]

This is young male Andinoacara coerleopunctatus, note the red seam beginning to show on the caudal, and white seam starting on the dorsal.
I wouldn't jump to any conclusions just yet, yours looks quite small
At a young age all Andinoacara look very similar, so of course it could have been easily mixed up, especially if its from a run of the mill LFS.
below a young female A. coerleopunctatus.