Sick Acan. Please help!

[NanaReefer]

Got it at a swap back in April. Very pretty with a red mouth. Low light was suggested, so I've kept in the back corner under the over flow box.
Parameters are spot on, all other corals thriving including another Acan.

When first bought

Today

 

[Tab28]

When i saw the first picture i thought mayan sun favia not acan. What kind of light are you using?

 

[NanaReefer]

See I thought it was Favia also but then someone said Acan. So now I better do an I.D. thread-lol.
I'm running LED's. 10mi/8hr ramping 30/50% max.

 

[Tab28]

Looks just like mayan sun. If so med light. But if u had it low slowly acclimate it. I never had luck with led too many variables for me. I keep my favia under 250 mh in a 24" deep tank on sand bed.