Kenya Tree Coral closed up for last month?

[happyclam]

Hi everyone,

I have a large colt coral in my 135g soft coral/LPS reef tank. The coral was bought as an adult speciment from Premium Aquatics and placed in my tank where it expanded wonderfully for at least a good 1-2 months. However, in the last month it has failed to open up even once. It is always 1/2-1/3 its expanded size, and only the tips of the polyps open up in the day. However, it still appears to be attached to its small piece of rock. Does anyone have any idea what could be affecting my coral? By the way, all the other corals have not skipped a beat and are expanding well.

1. Not enough light? It was under MH at the shop, where as my 72"x18"x24" is lit by only 4x96w PC's.
2. Rubberband toxicity? I used a rubberband to attach the frag rock to my LR structure and left the rubberband in the tank. Maybe it is decomposing and poisoning the coral?
3. Temperature sensitivity? Tank normally runs at 74-76 in the winter, but now in the summer it consistently runs at 80 even with all the heaters unplugged.

I know this is not nearly enough info, I will try to post pics and water parameters tomorrow to help give you a better idea.

Thank you for your help!

edit: oops, I meant Colt coral, not kenya tree

 

[happyclam]

I was scrubbing some algae of the rocks in the tank and decided to check out the base of the Colt. It appears to still be secured firmly to the rock (as best it can). It fell into a bit of a recess in the LR, so its base is kinda floating in the middle and then the edges of the trunks are attached to the edges of the rock. So basically, doesn't appear to be rotting.