If its not Aiptasia it will be majano anemones. Both are bad and I can't tell the difference as I have not had them, I think majano are browner.
Either way you need a blow torch or Seffies weapon of choice, a soldering iron. You could try Joes juice or Aiptasia X but they sometimes come back. Murphy's law, I bought Joes juice from ebay when I set the tank up just in case, this means I have never needed to try it, I will not sell it either as as soon as I did, I would find some.
Certainly looks like you have some hard work ahead of you, you could try an Emerald crab, some are great like mine, others like Trods moved rock, however I am having doubts with Trods as just after the rock falls she found an arrow crab, since getting rid of that she has not had any rock moving problems. (Trod if you read this, I have only just put that together)
Is this going to be the boyfriends tank??
It certainly has the potential to become a beautiful tank, good luck
