BTA will move around quit a bit before they settle. I would never put any anemone in a tank less than a year old. lighting is also a big factor in the happiness of any Anemone. What kind of lighting do you have?
I would suspect your BTA is in the tank some where. In a small crevasse of a rock. I do not believe the pump in a Fluval is strong enough to pull it in. But you never now. What about your skimmer?
J |