Can someone help identify if my fish has ich

[Dmk15]

I bought this sail fin tang yesterday from a reputable, national chain. I doubt that ich was in the tank as I have a few very susceptible fish, which is why I'm worried incase this on brought it in! I have a few pictures, but the quality isn't great as the tang won't stay still

 

[snorvich]

Describe what you are seeing (picture is insufficient)? What is the behavior of the fish?

 

[acrohead500ppm]

That is ich I see on the tailfin, and either your sailfin has some really unique coloration or its stressed to heck ! I am going to go with the latter, I really have never seen one so paled out before, and going off the comparision of the xenia enlongata polyps in the picture, I question if I have ever seen one so small either.

 

[Dmk15]

He's eating, not as quickly as I expected a (greedy) tang to, but this is his first lot of my frozen food since I bought him, so maybe it's because it's new.

I thought I should mention my parameters:

Nitrite: 0
Ammonia: 0
Nitrite: 0
Phosphates: 0.5

That is all my test kit can do

 

[Dmk15]

Acrohead

He is absolutely tiny, he's shorter than my pipefish if I'm honest!

His yellow is very vivid, but the black stripes aren't that prominent, I assumed that is because of how small he is.

 

[Dmk15]

Snorvich

He is eating, sometimes he swims erratically for a second, but he's not scratching or anything. He goes near the rocks but only to swim through the caves from what I can see