What's wrong with my yellow tang?

[JAKos]

So i bought a yellow taang about a month ago, he was quarantined for a month at the lfs and i left him in my qt for a week. i added him to the tank and he was perfectly fine eating alot swimmin with the other fish. well now he's not eating that much and sticks in the corner of the tank in a cave, doesn't come out often and sometimes i see him go sideways a little. i looked at him today and i don't see anything wrong with him besides a little grayish/white dot i can't tell if it's ich or maybe he has flukes? i've never dealt with flukes and he seems fine except maybe breathing a little heavier and only with that grayish dot. if need be i can pull him out of the tank and treat him in the qt however can flukes spread to other fish? hoping this won't affect my other fish..

 

[najer]

Can you show us your water parameters please and a picture under normal / white lights would help when the cavalry get here?

 

[JAKos]

Here's the pic

 

[JAKos]

Nitrates are 25 ppm or less phosphate showed up as 0 ppm the grey spot is hard to see but it’s like a pimple.

 

[nereefpat]

Any other tangs beating on it?

 

[JAKos]

Nah the only other tang i have in there is the hippo, which swims around everywhere haven't seen her beat him but the clowns showed aggression when he was first introduced.. maybe they bite him earlier?