Discus with one clamped gill

Hi All,

I recently bought 4 new Discus (3-3.5") in a planted tank about 1 week ago.
It now appears all of them are only using 1 side of their gill? and it's all on the same side (working gill on the left, clamped gill on the right).
I only noticed this last night.
It doesn't appear to be swelled or anything, and the fish are always coming out asking for food and appear pretty happy.
They don't appear to be scratching themselves on objects, or darting around the tank.

Tank Specs:
4ft 55gal
2 Aquaone Aquis 700 filters
1 UV Filter
Planted, dosing Flourish Excel Daily

Water Parameters:
Temp: 86F
Ammonia: 0
Nitrite: 0
Nitrate: 0.5
pH: 7.2
50% water changes 5x a week (with tap water and Prime)
The tank has been up and running for about 6months

Tank Mates:
4x Ottos
8x Cardinal Tetras

I wouldn't stress out about it. If the fish are doing fine, just monitor them.

Ok,
First sign of my discus scratching itself (Only one of them right now)
I have a photo of one of my discus.
Can you please tell me if it is Gill Flukes?
He is still coming out during feeding times so I am guessing it's not to a serious stage yet.Attachment 91019

Just fyi, he acts pretty healthy. I mean he hides most of the time. But then again so do most of my discus right now (still new I guess). They all seem to come out looking for food later in the night though. Ive only seen him scratch himself that one time today. Sorry if I'm a little over sensitive, but first time keeping discus and really want to have them nice and healthy.

the clear thing is a normal part of his anatomy. discus itch sometimes just like you do, and they scratch against a piece of wood. now if you see it a lot, like more than twice a day or something then I would say its time to worry. for now I would do some big water changes and keep observing, and observe from further away form the tank. sometimes when we get so close we notice normal things and turn them into diseases in our head :)

Just maintain water/tank cleanliness. Good water changes.