SOS: Acan Dying

[xLimitlessJR]

Please help!

I have a small Acan colony dying off and i cant figure out what the heck is going on. Its right next another small colony (to the left in the pic) and right in front of another frag (which isnt visible in the pic), the other two are doing great and all 3 went in at the same time. Also they are not touching (which im not sure actually matters).

Up until last night it didn't look super happy but its tentacles were extended which i took as a good sign, but late last night and this morning it looks really sad.

Any ideas???

 

[dank reefer]

Do you happen to have any peppermint shrimp in your tank?

 

[xLimitlessJR]

no peppermint shrimp, relatively modest CUC too, very confused