Any idea what is wrong with this guy? Zebra Danio

[Stlshrk]

Here are a couple of pix of this Zebra Danio that has part of its head / face turning white.

I don't see any open sores or any build up on the surface (no cotton looking growth).

There are no other white dots on it, so I don't think it is ICK.

None of the tank mates show any symptoms.

She/He is the tank boss and a very enthusiastic feeder. I almost wonder if it didn't injure itself digging into a tight spot for a bite of some morsel?

The fish is not doing anything strange and is still very active.

Tank parameters:
55 gallon community planted.
0 Am, 0 Nitrites, 5 Nitrates. Ph 7.4. Water Hardness = liquid rocks...
Low tech with a liquid all in 1 fert dosing (Thrive C)
Most recent water change was yesterday.
Temp maxes out at 75 degrees and down to 73 degrees by controller.
I double check the temp with a stand alone thermometer.

There have been no new additional tankmates in over a month. And at that point I added some Olive Nerite Snails.

Am I being too cautious or is this the onset of something?

Sorry about no head on photo. I took over 40 just to get some that were not blurry.

Thanks folks!

 

[Jessiejnumberonefan]

Hi, hope all is well,
He may have been stuck somewhere? If so it may be damage to the scales, it’s not something to worry about, keep an eye on him and if he’s still acting like himself he should be absolutely fine I’d imagine his scales will heal soon. Some fish lose their colour, as long as he’s acting fine he should be fine

 

[Stlshrk]

Well, I thought that he/she was on the mend. The white on the forehead had lessened over the last few days. Last night I did a algae scrub and water change. Then this morning the guy looks like this.

Any ideas?

 

[Stlshrk]

R.I.P.