I got lucky with my BTA... it found a nice hole in one of my live rocks that it can completely suck itself into if it desires (and it has). It just so happens that it is directly in the front of my tank, so I adjusted the current on the powerheads so that it gets blown about a bit but not too much.
So far it hasn't given any indication that it wants to move and is happily inflating its tips and putting up with whatever the clowns dish out.
The small carpet I had, on the other hand, never could find a spot that it liked, and wandered nightly after lights out until it happened to wander into my elephant ear mushroom colony... and the rest is history.
It was just a glob of goo the next morning.
