I captured a photo of the most strange and fascinating myserty creature
emitting a constant plume into the tank. The trail of smoke appears
transparent, and flowing in vortices similar to what you would see in a wind
tunnel. It continued ejecting this material for hours, seeming to have an
endless supply. Then in the days following, many of my corals died.

The mystery can be seen just below and right of center:

http://www.autonvs.com/images/MysteryReefPlume.jpg

Thanks ~ Dan