BTA bubbling seems to be associated with light

[Ardeus]

One of my BTA's spends most of the day in this shape:



As you can see, the tentacles closer to the light form bubbles. At night time it transforms again, becoming smaller with different kind of bubbles but all over.

The other BTA's also behave this way but not in a so exaggerated form.

 

[bshow24]

Overall it depends on the specimen. Mine don't behave like that at all, but mine have a different personality.

Good observation for yours though, but they'll keep you guessing and next month it'll change haha