I dont think Calgary would have many shops selling arowana. Did you buy yours in Calgary or elsewhere?
Awesome red. Shelook red are becoming more and more popular these days.
How long is your tank?
Btw he might be a bit shy because of the direct sunlight near the window? That's what I noticed with mine a while ago but then again sunlight is supposed to be good for tanning.
Also DE might associated with the school of clown loaches and rays you have. Just a thought.
DE stands for drop eye, a condition where one or both eyes start to look down... lots of theories as to why it happens, so far no concrete reasons why or how it happens...
From the pic its not that noticeable, could even be the shutter closed when the fish was looking down.