hello all, I believe there may be an issue with my red tailed shark, it doesn't seem to be growing much. I've had he/she for a couple of years since it was a little baby but he/she has only grown a little and not really fattening up like some of the ones I see in other people's aquariums. You know how it goes and like anyone else... I never see it eat. The behaviors I've noticed are; slowly swimming around the tank, swimming in place with head tilted downward kind of bobbing around. Also sticking to the glass right behind the powerhead when it's not on.

I just thought he/she would've grown bigger by now, even one of the Buenos aires are getting bigger than it.
Any help or suggestions are welcome, thanks... oh and btw it's in a 55
Gal bow