My five year old female sebae anemone spawned several times last year. In each occurrence it was after the lights had gone out. Eggs along with white fluid was released into the water column clouding up the tank and collapsing the foam head in my Becket skimmer for a full day. If you haven’t done it already I'd strongly suggest a big water change or the spawning event could nuke your tank like what happened to this guy:
http://www.reefkeeping.com/issues/20...totm/index.php