He is doing a bit better today in QT and able swim around sometimes, but still not eating him favorite nori and stay in corner most of the time. Thanks all for helping and I will continue keep close eye on him.
@Jay Hemdal, I saw your force feeding in another thread and wondering should I consider force feeding him, since he had not been eating in 3 days. Or should just monitor for another day or two and see. Thanks again for your help.
No - I would not try force feeding yet, that is very stressful. Fish can live for one to two weeks with no food, and can recover if the original issue is fixed.
Jay