I have a 3 1/2 yr. old Frontosa and when he was small, he liked to hide in pvc pipe or a cave. Now that he is full grown, he just hangs towards the middle-top of the tank. Is there anything I could put in my 110 gal. tank for him to go in? Most of the other fish in the tank are smaller than he is and go for the caves, behind rock or slate. Do the frontosas need some kind of place to get into?