What Is Wrong With My Sun Coral?

[krzyphsygy]

I have had this guy for about a month or two. I feed him regulary chopped pcs of shrimp, cyclopeez, reef chile, pe mysis and i do it several times a week. It eat with vigor and was doing really well.
All of a sudden today it looks really deflated....polyps are extended, ut are deflated looking. The pic shows them with all pumps off. See how they are kinda limp...not sure whats going. Thought someone might know??

 

[krzyphsygy]

Here's My Perameters

N03 0
Phos 0
Cal 435
DKH 7.7
Mag 1410
SG 1.024


All other corals are good. Acro's andother SPS have full polyp ext.