Fish's head turned red, possible disease?

  • We are currently upgrading MFK. thanks! -neo

scissorfight

Feeder Fish
MFK Member
Sep 5, 2006
23
0
0
Norway
My bala shark's head has more or less turned red, it behaves normally and eats well. I see the same tendencies in other fishes too.
Better safe than sorry as the tank contains fish for a couple of $100. But I can't find these symptoms anywhere in my fish diseace literature. I wonder if anyone knows of a disease with these symptoms.

Could it come from feeding on pellets containing red color enhancer?

Water parameters

Ammonia 0
NO3 10
NO2 0
GH 6
KH 0
pH 6,4

Please let me know what you think
-thanks

fisk 044 (Custom).jpg

fisk 048 (Custom).jpg

fisk 050 (Custom).jpg

fisk 051 (Custom).jpg

fisk 052 (Custom).jpg

fisk 057 (Custom).jpg

fisk 060 (Custom).jpg

fisk 062 (Custom).jpg
 
I have never seen them do that.
 
MonsterFishKeepers.com