Take my advise, don't try to keep it.
What happen to me is that it killed my blue tang, yellow and pupple tang.
You can feel that it's so sticky to your hand, witness my fish caught one by one by this fellow, i even had a hard time trying to release the fish from it, in the end the whole tang was stinged to death eventhough I can release it.
This carpet will hide it's base in hole of LR, and extend big ready to prey. I was so pissed until I use a plastic bag to cover the LR, forcing it to move away. Finally it moved to the sandbed where I can finally remove it..