help with chromis, possible popeye? please read.

i bought a couple chromis a few days ago, one was missing for awhile.
i found him under some rocks (not squished, he was fine) - but he wouldnt start swimming or eat. i put in him in a little container i have in the tank hanging on the inside.
he has been "free" from the rock since last night and i havent seen him eat - he also seems to have popeye or some sort of fugus? i read that stress or like abrasions can cause a simliar look (like popeye)
what should i do? if it is popeye ive read to use maracyn 2 and if its not, i should leave him alone and keep an eye on him.
thanks for the advice in advance!

 

I think you should remove the fish from your tank, put it in a ten gallon or suitable container.  Use a sponge filter, heater and treat with the recommended medication.