If your visiting computers stores consider the iXtrema Pro Quiet Fans by SilentX. There 120mm fan has a dBA of 14 at most, compared to say a range of 25 to 40 for other fans.
That is to say it's about 1/2 as loud of most fans on their lowest speed setting! Be sure to ask for SlientX by name...
This is a great article that inlcudes some of the comical nature people seem to love about Jawfish:
http://www.reefkeeping.com/issues/2002- ... /index.php
It mentions a Jawfish defending about a 12" perimitor around their den from other species, but on the topic of two or more Jawfish; "4' tank...
