New fish not eating - stress/bloat ? - when to act?

[Adam GR]

So here is my 3in unknown hybrid hap - he entered my 90 gal tank 6 days ago and I didn't see him eating anything. Yesterday I saw him trying to eat but he spits the food. I tried variety of food - pellets, flake, frozen. I didnt see his poo.
He is in malawi setup with 15 other males, most of them bigger then him, some 6in. Surprisingly he is not really bullied by anyone.
All water parametrs allright.
So the question is - could it be strees or bloat? Or maybe something else?
Should I take him out and treat (I have octozin - waterlife) or wait a bit more?

 

[DJRansome]

Malawi can go without eating for a month so too early to worry about that. Don't try different foods, he will eat when he is hungry enough. Keep watching for feces.

Where does he hang out in the tank? If he is lurking under the surface or behind heaters or filter intakes, I would isolate him but not treat.

 

[Adam GR]

Malawi can go without eating for a month so too early to worry about that. Don't try different foods, he will eat when he is hungry enough. Keep watching for feces.

Where does he hang out in the tank? If he is lurking under the surface or behind heaters or filter intakes, I would isolate him but not treat.

Well he is swiming freely all around the tank. Im really surprised how easy he adapt to tank, no one bothers him. He came in with red shoulder peacock (1.5 in) who all the the hides but eats. Thats why I am a little worried.