Jeanna,
I'd hold off on nuking the second one.
I have had mojano's. And they never looked like that. There is usually a much wider area clear of tentacles around the mouth of a Mojano. I am betting that Shao is much closer to the guess. It looks more like some form of ricordia or other corallimorph to me. But that is me. How much does it retract at night? Does it retract?
As well Mojanos appear a lot greener with brown or pink tips that elongate as they grow. by the size appearance of your's they tips should be a bit more elongated. Actually much more.
Post that picture in Eric B.'s forum on RC. Best bet. You may have something nice there.
take a look at this search and you can see that pretty much every Mojano has a similar appearance. Like I described. Tho I could be off in left field.
Still if it isn't reproducing like a weed. Why not get a complete ID and see from there. It can't hurt.
http://reefcentral.com/forums/search...der=descending