Anemones have the advantageous, and sometime anoying, ability to move on their own. When you put one in, you really have to accept that it is going to find where it wants to be. This is maybe not where you want it, but if you put it where it is not happy it will wither away.
I am of the opinion that anemones should really be put in their own tanks; with proper lighting, current, and other needs. Becuase they can walk, if you have a Power Head in the tank it can puree them. They really need to be able to move about the tank without the aquarist worring that his or her prized SPS coral is not going to die.
I had a bubble tip in a fifty. I put it in where I felt it would get good current and light. It moved less than an inch and stayed there for 6 months. Then one day it started on up the reef, I had to remove it because it was going to kill a number of really nice corals as it went. Since then I don't trust them.
Oh well enough ranting
Luke