Just for the sake of murphy's law I wouldn't rule out a health problem. However from my experience these guys are drama queens. My guess would be he's a little stressed and pouting. Now just from the pics it looks like you don't have that much cover. All mine liked to have one big hideout (like driftwood) then a few plants to go swim in between. Once he gets comfortable he will dig his own trenches to hide in.
Now once they reached 12"+ they would cruise more in the open. Just my experience.
Now once they reached 12"+ they would cruise more in the open. Just my experience.


