Gbta upside down

[bighead]

I have a green bta for about 4 months now and the last two weeks he has gone under a rock and has been hanging upside down out of the light some days he hangs low and looks good and other days he is contracted and does not look to good . he has always looked good and pretty open since I have had him . I shoot him some food about every 3 days when I feed my corals and he seems to eat I would just like to see him
Should I worry yet
my par are
SG 1.025
am 0
trite o
trate 0
cal 460
alk8.5
ph 8.1-8.3
mag 1300

I have a 4 lamp t-5 fixture and my tank is 90 gal with a 40 breeder sump and I run a skimmer

 

[tatuaje08]

If its eating and looks ok, no need to worry.

 

[Sagz70]

He may be going under to split.. who knows.