Jack Dempsey problem on sides

Hey everyone. Stopped by my tank tonight and noticed my JD had a very odd stripe down the side. I haven't seen this guy looking this unhappy before. I'd appreciate any ideas on what it could be.

The stripe is roughly the same on each side. He's about 10" long.

taken today:




what I'm used to from the last pic I shot (it's a bit old, he's grown quite a bit since then, but you get the idea):

It's a 125 gallon.

I'm changing bi-weekly usually about 30%. I've got an impeller down on one of my canister filters right now (shakes fist at Penn Plex for hard to find spare parts) so I'm running with just one of my filters. But, I was doing some serious overkill with both.

Feeding basic Hikari food, about every 2-3 days.

Guy's been a champ since I got him about 4 years ago from the fish store for $10, put on about 4" since I got him.

I think I might bag him tomorrow and take him into one of the LFS tomorrow and have them take a look as well.

Bah, it's water quality. I'm doing a change tonight and will again in a few days. Hopefully it'll clear up.

Don't suppose anyone knows where I can get an impeller for a cascade 1500 canister filter do you? My Fluval 304 isn't cutting it by itself.