Thoughts on my RBTA?

So after having my 30g up and running and everything going well with some corals I decided to try BTA again. I got a RBTA from my local LFS on 3/19/16, drip acclimated him and everything was fine. That was a Saturday. By Sunday one of my marroon clowns were hosting. The RBTA found a good home where he had his foot between 2 pieces of LR. Seemed very happy with the clown as well. I witnessed the clown feeding the nem when I fed frozen, this is awesome!! Now the other day I've noticed he has moved to the back on the tank completely now, and is completely between the two LR's not exposing himself (at least when I'm watching). The clown still is hanging around him but from what I can see he appears to be shrunken up (similar to first picture).

Only thing that has changed in my tank is that I went from IO to RC salt. But still a slow move over. I do about 10g water changes every week. My alk has dropped from 11 to 9 with the new salt, could this be making him unhappy? As I said tank has been up for a little over a year. Everything is under a ReefBreeders Photon 24"

Alk 9
Ca 340
Mg 1185
Nitrite, Nitrate 0
Ammonia 0
Phosphate 0 (do have a small hair algea problem)
Ph throughout the day is 7.85-8.44
Temp is 78.2-79.9
SG 1.025

Any suggestions? Or is this a normal behavior for a RBTA? Again he's been in my tank since March 19th.

Thanks,

Blair