had to chime in on this one.....
i have one of these in my 75. he is about 4 - 4 1/2 long right now, markings are starting to change.
everything i have read here and anywhere else states that they are diggers and tunnel makers.....
mine never goes to the bottom or anywhere near the sand. top 6 inches of tank.
he's healthy. eats, plays in the current, not gasping for air. eats just fine with everybody else.
just curious as to why he's always up there?
any insight?