Angelfish not eating

Question
Hi,
I'm worried about one of my angelfish that just sitting in the corner behind a plant most of the time.....now and then he swims around but not much and when it comes to eating time he still just sits there while my other 3 angels attack their food like piranha. He hasn't eaten in 2 days now. He is breathing normally, there is no one bullying him and there are no outward signs of any injuries or disease, infact he is a perfect specimen of a silver zebra angel. He is in a 55 gallon tank heavily planted with lots of driftwood, triple filtered, two airstones, water quality is excellent...Ammonia 0, Nitrite 0, and Nitrate 5, and a PH of 6.6......WHY does he just sit in the corner and not eat?????...please help!!!

Answer
Hi Dave,
Is this fish quite new? If so it will take him a few days to get used to his new home. If this isnt the case then i would say he has internal parasites. When a fish has internal parasites they usually stop eating for no reason.
To treat use a medication called Prazi.

Good luck
Chloe.