Ocellaris clown, possibly sick?

[Turbosnail]

My tank was purchased cycled w/fish, I have traded most of them off except the clown. The tank is a 29 gallon w/live rock. A few days ago I changed the substrate from crushed coral to sand, I did this to get rid if the under gravel filter. I now use a bio wheel 200. Last night I tested the water and came up with ammonia between 0-.25, nitrite at .2 and nitrate around 5. Probably a mini cycle, due to not enough rock. I did a 50% water change. Nitrite is now less than .1, the clown has two little grain of sand size brown spots on his white band around his head. Other then the spots he looks fine. Does anyone know what this is? Thank you for your help.

 

[Turbosnail]

I went and purchased a new test kit, mine apparently was expired. The ammonia and nitrate are at 0 and nitrate is 10. The little spots are still there though, if you look really close it kind of looks like the white scales have been hurt.

 

[David S]

He may have just got knocked against the LR,