Just to give another perspective - I've had BTAs for several years, and my experience is that they will move when conditions change, often after staying put for long periods of time. Your bulbs will age, you'll add a coral that they don't like so much, change the flow slightly, etc., and off they go. If you're going to keep anemones, you need to work hard to keep things stable and either (1) keep corals that you can move out of the way if necessary, i.e., specimens that don't grow onto the rock; or (2) resign yourself to the fact that your anemone may move somewhere you don't like and that you may lose a coral or two over time.