LPS recede and shrink!!!!!!!

[mandarin man]

Hi all,

I am just wondering if anyone experience a similar situation as I do. My LPS coral fully expand nicely after three to six after the photoperiod (when the lights are on). However, toward the end of the day some of the LPS tend shrink up and recede one or two hrs before the lights go out. My photoperiod is 8.5 hrs with T5.

I guess is that the coral cell (Zooxanthella) saturated with light or the lights are too intense. Is this normal? Your inputs are welcome.

Thanks

[Marlin65]

Mine stay fully expanded at all times under 400w M/H. Even after my lights are out they are still mostly expanded to full capacity.
How many T5's and what watts are you running on what size tank?

[Leah]

A few of mine do as well. And I am using T5's as well 4-54 watt on a 72 gal.

[mandarin man]

It is a 34gal RSM, 110W T5.

[mandarin man]

I think it is probably the T5 causing constant illumination at the coral.