Tusk behavior

[tijil]

I just got a 6 inch Australian harlequin tuskfish. He's a lovely creature and, to my knowledge, acclimated wonderfully. He is eating well so far. Here's my question, though, what kind of behavior do these creatures have at night? Mine seems to get more active at night, patrolling swiftly about the cage, always trying to swim out of the tank. My lfs owner insists that they don't need a deep substrate to sleep in, but I have areas of 5 inch deep substrate, just in case. However, the tuskfish doesn't seem to use them. As I said, he just gets more active at night, staying awake long after I do. Then, when I see him in the morning, he is sleeping at the surface, in one of the corners.
Is this normal behavior? Or perhaps he's just not adjusted to the aquarium? Does he need a deep region of substrate? What kind of substrate should it be?
Thanks in advance,
--TiJiL

 

[dockery07]

I have one mine spends the day sleeping in the corner of the tank and is out and about at night. Mine does not pay any attention to the sand.

 

[irenicus]

Mine sleeps on top of the sandbed in the corner at night.