Some people have had clownfish "love" lps to death. While they may enjoy being hosted by it, they can cause damage to the coral - just an FYI. Of course, others have had clownfish being hosted by lps for some time without any harm to the coral. I just wanted to let you know there is a risk to the coral.
You mentioned that your RBTA never stayed put? What did you do to attempt to keep it from moving. There are a number of causes for a BTA moving:
Here's my thoughts on the matter of wandering BTA's:
On the topic of a BTA moving "all the time" as some say...I would argue strongly against this statement. In my experience, from reading, and discussions with other people with far more expertise than me, a BTA will remain in its spot if all of its living conditions are being met satisfactorily. There is no benefit to the anemone (risk of being stung/sliced by corals, risk of not finding another rock in the ocean, predatory animals, etc) to "just move around" IF all conditions are appropriate.
Water quality, light, food, Flow, and foot - the five conditions that must be satisfactorily met for all anemones.
Water quality: In the ocean, if local currents drastically change after storms, rivers dump crap into the ocean etc, the nem may want to move to conditions which better suit its liking. In our tanks, however, there are no other areas which have better water - but the anemone doesn't know that. This is my #1 pick for why anemones move without apparent reason. It may even be something in your water which you do not test for - or it may be BECAUSE you just did a water change and didn't match tank water close enough. The anemone is searching for something it just can not find inside a glass box, hence the so called "anemone's just sometimes walk around for no reason". We can't see the reason - so we assume there isn't one.
Light: Lighting in the ocean is quite strong. Far more than our little electrical lights we use. Even on a cloudy day the par is very high - ever had a sunburn on a cloudy day? When you introduce a BTA, you may have a spot picked out that you really want it to go, but it may decide it is too bright or too dim and promptly move. As it gets light-acclimated to your tank, it may move to a spot that is "just right" for its health in the long term. This acclimating and moving to a new home may also cause confusion to BTA's "moving a lot".
Food: Yikes! There is a lot of misconceptions about the "proper" diet for anemones. I did a write-up on RC a while back about the topic:
http://www.reefcentral.com/forums/sh....php?t=1835320 A basic summary of that thread is.....assuming a healthy nem, food is likely unnecessary. If you would like to feed, feed small (pencil eraser max) meaty, raw, SW-found foods. Unhealthy nems need more food to gain energy and should be fed more. Feeding leads to faster growth. Feeding can also in some cases overcome less-than-ideal lighting because the food is supplementing the light source. More in-depth information can be found at that link.
Flow: You need to determine the flow requirements of the species of nem you want, and make it match in order to decrease the likelihood of movement. BTA's will like moderate flow, but not too high or too low. Either of those may cause it to move around. Some can be very picky. I know someone who's Haddoni moved across the sandbed after her cleaned a powerhead and replaced it (he thought) in the exact same spot. Apparently it wasn't quite exact. Haddoni's like low flow - if their oral disk is being moved by the current, it's too much and will cause it to move.
Foot: This is my #2 reason why BTA's apparently move without known cause. The foot of most anemones also requires special concern. Some anemones like to bury in the sand, some at the sand/rock interface, and some directly onto rocks. BTA's like to have their foot in a deep crevice, hole, or cave. Basically, it's a safe zone for them to hide in if they need to retract. It's also a way for them to regulate the amount of sun it gets. These deep holes are key to keeping a BTA happy with it's current spot. They like their foot shaded, and head out in the sun.
Hope that's a good summary of what I think about BTA's.
I get a little discouraged with people when they have stories similar to your own. It's not that BTA's always wander, but it is up to us to keep good husbandry of each inhabitant and read their signals, decode them, and give them the best environment we possibly can. Merely saying that everyone should not keep BTA's in a reef tank is a bit short sighted and is ignoring the fact that the anemone is wandering for a reason.
