http://www.reefkeeping.com/issues/2002-11/fm/feature/index.php">http://www.reefkeeping.com/issues/2002-11/fm/feature/index.php</a>
They list 30 gallons as minimum tank-size for a dwarf lion-fish, and I think even that is a tad small, even with absolutely nothing in the tank besides 1/2" of sand - [I][B]no[/B]</em> rock-work whatsoever.
IMNSHO, of course, but I think your tank is just too small.