We have 3 in our 210g. For the most part once they find a spot they like they usually stay put. Any corals around them do have to watch out. One of ours moved onto a nice patch of blastos and promptly killed them.

We have a couple who are happy in moderate flow and one sitting smack in front of our vortech 40. Our RBTA clone from Bill's brood stock liked the first place we put her and has stayed put ever since.

Good luck with yours, hopefully she will find a place she likes and stop her wandering ways.