Why is my BTA so stretched?

[mrhasan]

It has been in my tank for around 2 months now, moved twice until now (initially settled within few hours, remained there for over a month and decided to change the spot about 2" away, didn't like it and went to the new spot and have been there for a week or so; knock on the wood). It started like this:



Stayed like that for a week or so and once acclimated, it looks like this:







Seems to be eating fine, starts the day with bubbles (bluer spectrum) and looses them over the day and then becomes smaller during the night. Don't have any experience with the different "state" of a BTA so any expert advise on this would be appreciated Tank water or tank does not need any troubleshooting.

Thanks in advance