My Elegance hasn't extended all of its tentacles in a while. Any ideas?

[wartooth1]

So I've had this cool looking Elegance coral in my tank for a while now. Lately, it hasn't extended its tentacles. I asked about this at my LFS where I got it from, and they suggested I increase magnesium dosages, and that has helped a little. I also read that Elegences tend not to extend their tentacles when they're in a strong current, but mine is in a spot that probably has the weakest current.
Here's a pic of what it typically looks like now:

As you can see... the tentacles from its 8 o'clock and its 5 o'clock positions have its tentacles extended ok, but the rest of it stays stubby.
Any ideas?
Thanks.

 

[geoj]

Looks like it is getting chewed on

 

[wartooth1]

You think so? How can you tell? The tentacles don't look chewed on... they just aren't fully extended, as far as I can tell (all tentacles still have their pink tips).
Oh and FYI before I started dosing with magnesium all the tentacles were short. Now that I have been dosing magnesium, almost overnight the tentacles you see that are currently extended came out, but the rest of 'em remained stubby.

 

[spanko]

Are you testing for the mag? Be aware that if there is a rule of thumb here it is that the mag level should be rougly 3 time the calcium level. So if you have 450 on calcium then you mage should be around 1350. Balance is what it is all about and check your alk also. Alk at those levels for calc and mag should be roughly 4 meq or 11 dKH.

 

[geoj]

There is something different from one side to the other. If it was water quality and it may still be, the entire coral would look the same. This is why I was thinking it had been nipped at. :%%:

 

[wartooth1]

Now that its been brought up I have noticed my diamond goby nipping around the tentacles to get at the sand under it so I suppose its possible that this is annoying the elegance.
Strange thing now is that I did my routine water change over the weekend and tested for imbalances... everything looks decent but now the elegance completely closed up... all other corals are fully opened. The last time I did a major water change the elegance was really happy and opened up quite a lot but this time it had the opposite reaction... got even less happy after the water change.
I know elegances are supposed to like the sand but do you think it would be ok to put the elegance up on a low rock so that the diamond goby stops bothering it?

 

[geoj]

I would try moving it to a different part of the sand in lower flow just to see what happens. I read is should not be put up in the rocks? :%%: