I have 16" Redtail Catfish and 32" Black Pacu. For the last past few weeks... they won't eat anything. I'm doing the water changing but nevertheless... I been trying to figure out why they are not eating!! The Catfish love to eat raw liver or raw steak.... yet.. he been sticking his nose up. Also.. the catfish been swimming up on top alot lately and it seem like its getting bit redder around his lip. Any idea?