Looks like a
Pseudocorynactis sp. anemone.
Or possibly a
Corynactis sp. anemone.
(I get the names of those two mixed up since they're so similar.)
Harmless and mostly nocturnal (ie. more apt to come out when it's dark.) (Although I've read that they can be trained to come out during the day if target fed, and the mechanism by which they can predict when feeding time is about to occur is unknown. Cool huh?)
Related to those Strawberry anemones we see along the Pacific coast of North America down by California (I'm not sure if their range extends as far north as BC .. at any rate the one you have in your tank is not the same species but just a relative from the tropics).
http://www.marinelifephoto.com/inver...ges/CAI-20.htm
http://www.martysnyderman.com/cgi-lo...jpg&img=20&tt=