Need advice for my clownfish who I noticed is not eating brine shrimp and is mouth breathing

[SparksterRocketKnight]

So I have a problem and decided to finally try to use this site for some help as a lot of the posts I read on here are very helpful. Occer Clown, Got him 2 weeks ago and was fine. Eating correctly, and was wandering the tank with high energy. Recently did a water change and did the usual, measured salt, put in stress coat to rid tap of bad stuff. Nitrate and phosphate levels are very low. Seems to breathe heavily and only hang around my royal gramma in one area, which appears fine. Heres a short video so you can have a look at him:

 

[vetteguy53081]

It detoxifies chlorine/chloromine and metals.