Supernova tentacles retracted

[jasonyin]

Hi everyone! I got this nem about 3 weeks ago. When I first got it, all the tentacles were fully extended. Over time, some tentacles (circled in red) are retracted so they look smaller and brighter. The number of these retracting tentacles is increasing, but the body is fully open. Anyone know what could be happening?

 

[Uncle99]

Parameters?
Age of system?
Light?

 

[jasonyin]

ALk 8.1, CA 415, Mag 1280
Salt 35
PH 8.1
Temp 80
Nitrate 3-5
Phosphate .03
System about 7 months old with other SPS, LPS doing well
Radion XR 15 Blue , and the position is as shown in picture.

 

[jasonyin]

@Uncle99