Rainbow montipora acting strange

[JazzChing]

I have this great rainbow montipora for almost a year. But it is closing partially for almost a week! Am I too aggressive or it is something wrong with it ?

 

[homer1475]

Parameters?

It looks to me like it might be getting too much light? The top is loosing it's polyps, while the edges seem to be fine.

 

[JazzChing]

Parameters?

It looks to me like it might be getting too much light? The top is loosing it's polyps, while the edges seem to be fine.

Unfortunately I did not have any changes with the lighting and the flow but my hermit crab stays on it quite some time.