
Here is an update pic of his head that shows how bad this is:

That's a much more sensitive fish, probably got shocked by a temp change or something like that.If all else fails, try water change only 30% water at most. Last time I did 50% change in Feb, my 4" Albino Barb died and almost lost the other one. Which mean something is totally wrong with the water.
Best of luck for little Aimara though.
Agree with the guys, bb might be low. Let us know how the test comes alongI will be rerunning the ammonia test again today and we will see. If ammonia comes back at 0, I will do a 25-30% water change. I am more surprised that my nitrates continue to hover around 20. Would think they would drop to near zero with that much water being changed. I have only 1 decoration in the tank and bare bottom so its unlikely for me to have food hiding somewhere.
N nzafi I actually meant to ask before I got side tracked. You mentioned you're running a HMF, So your running a Hamburg Matten Filter? Was the filter already established? I ask because while HMF are extremely efficient and rival even the best filtration methods as far as I know they take longer then others to become established.
Do you have any other established media in other tanks you could use to jump start a secondary filter? Maybe a HOB as a supplementary filter. While I know none are rated for a tank your size between what ever is established in the HMF and the low bioload since you only have the wolf it may help.
Do the wounds on the wolf's head look like they're getting better, worse or about the same? If they seem to be about the same or getting better he might benefit from a triple antibiotic ointment. It might help act like a protective layer while promoting healing. I'm pretty sure Aquanero had suggested it to me at one time or another for fungus. And while I know this isn't fungus it might help because it might act in the way I described above. I wishAquanero was as active as he used to be. I tagged him just in case he happens to log on as he's good with advising people on stuff like this.