Acantho not opening

[gonzo256]

I have had this acantho for about 4 years, and it's been in this iteration of the tank for the past 15 months. Over the past week it hasn't been opening/spreading out as much. It's not completely closed or shriveled. It's just not as large and active as it has been in the past. It's color is good and doesn't show any signs of necrotic tissue or damage.

I have dialed down my light intensity a by about 10-15% and my parameters are:
pH: 8.0-8.15
Alk: 8.7
Calc: 440
Mg: 1400
salinity: 35.5
Temp: 78.0F
Ammonia: 0
Nitrite: 0
Nitrates: 2

My other donut is super happy as is all the other corals in the tank. any suggestions?

 

[Crabs McJones]

I have had this acantho for about 4 years, and it's been in this iteration of the tank for the past 15 months. Over the past week it hasn't been opening/spreading out as much. It's not completely closed or shriveled. It's just not as large and active as it has been in the past. It's color is good and doesn't show any signs of necrotic tissue or damage.

I have dialed down my light intensity a by about 10-15% and my parameters are:
pH: 8.0-8.15
Alk: 8.7
Calc: 440
Mg: 1400
salinity: 35.5
Temp: 78.0F
Ammonia: 0
Nitrite: 0
Nitrates: 2

My other donut is super happy as is all the other corals in the tank. any suggestions?

Is anything bothering it? Any new invert additions that may be crawling on it? I would stick with dialing the lights down and see if he improves as all your parameters seem to be good. Any pictures of it by chance?

 

[gonzo256]

No new anything has been added.

Is anything bothering it? Any new invert additions that may be crawling on it? I would stick with dialing the lights down and see if he improves as all your parameters seem to be good. Any pictures of it by chance?

 

[gonzo256]

I checked underneath, and there is some tissue missing and you can see a portion of its skeleton.

Help?