I got mine a week ago - it opens and closes daily.
It does get REALLY open, and then REALLY closed!! It closes to the point where you think it's dead at like 3-4", and then in the morning it'll be like 8" wide, tentacles extanded.
It's also climbing ALL over the place!
Up until the Ich attack, my O Clowns didn;t pay any attention to it, so I'm going to try what others have said, and get a smaller tank, and put the GBTA and the clowns in there for a few days and see what happens.
I also have a LTA in the tank as well. It does the SAME thing.
You'd think it was dead, and then in the morning BAM! It's like 4-6" wide, and happy as heck!
My wife calls these the Sopa Opera of the Ocean.
It;s dead - it;s alive. It;s dead, no, wait, it's alive.
They are cool, though, especially watching the GBTA move all over the place!
Tony