Can this be fin rot?

[Crazylot]

I have had this angel for about 4 months now. It eats amazingly and it's always swimming around everywhere. For the past 2 weeks it seems like when it goes to sleep it hides under something cause I can never find it. And now I just noticed its fin and now it's always hiding int the back. I think it's sick with something cause he is not the same. Some of my plants died in the water and I just took them out, looks like they where dead for a couple days so maybe that is the cause?

 

[Painted skin]

First what is your water parameter? A closer look pic would be helpful.

 

[Occane5]

Have you tested your water quality? Could also be aggression from other fishes.....like the clownfish.

 

[MrTuskfish]

What kind of plants?