Is it fully attached yet. You could turn your PH's off in the tank, until it attaches its foot, then it will move to find the spot it likes when the current is back on. Just a thought. Hopefully it will stay in one place for you. Everytime I would change something in my tank, mine would move around and sting(kill) my corals, it now lives in my fuge until I get my 29 going. Actually, it is two of them, I ripped it in half trying to move it out of my DT. Good luck, I hope you have better containment of yours(darn things have a mind of their own).
Matt