Is it Brook, Velvet or Ich?

[ItsNiQi]

I first noticed about two weeks ago that my young Photon Clownfish showed a slight difference in appearance. Since his eating habits haven’t changed and his overall demeanor was the same I said I would just look over him for the next week or so. Today I looked at him and it seems to have gotten worse. First thing I thought was brook since none of the other fish are showing ANY signs of distress. My other photon seems good also. I decided to give him a freshwater dip for 4 minutes. Not much was left behind in the bucket and he seems a bit fuzzier. This video attached shows him two min after dip. Can anyone help identify this problem?

 

[ItsNiQi]