I have what I believe is a BGTA but I am not 100% because it has never "bubbled up". I do also want to know if I should lower the light a little on my tank if that may be a problem. It is a 150 watt MH sitting about 16" above the top of the Anemone when it is extended. Anyways... here are some very poor pics to go by.
Blurry top down.
Head on
Blurry top down.
Head on