With regards to the growth on the side of your koi, could you please take a clearer shot of the area in question at the moment it lacks the clarity one needs to identify what it is .
Is there a possibility you could take a shot of this side of your koi behind glass i;e fish tank....
At the moment it looks to be a damaged scale hanging from the side of your koi , which if this is the case will drop away when its good and ready too .
However the redness you can see could mean the wound has become infected, but like I said we'd need a clearer shot to give you a propper I.D.
