I might try moving it into the middle of the tank just to see what she does. But when she gets the angle just right, and can catch most of the bubbles under her disk, she'll just float there barely rippling her fins. She won't move for 10 or 15 minutes at a time, unless she gets unbalanced and starts to float to one side. She's even let me reach in and "pet" her a few times without reacting when she does this...