Orange Back Fairy Wrasse

I have a 46 gallon with 2 oscellaris clowns, 1 mandarin and an orange back wrasse. For the past few days the wrasse is not coming out to swim even when I feed the tank. I don't know if he is eating at all? I see him in different areas in back of rocks so he is alive. I have not added anything new so I can't figure out why he is acting like this. Ph is 7.8 - 8, alk is 9-10, calcium is 420 and temp is 78-79. I used 1/4 teaspoon kalk to 1/4 gallon water morning and night for top off water. He used to be out in the open all the time except when the lights go out then he would go in back of the rocks. Now he is not coming out from the back. Any ideas?
Adam

 

The pH is a bit low but that shouldn't be it... have you added anything to the tank lately?

 

this is a double post

 

Orange back Wrasse

Nothing new was added except that I raised from 77-78 to 78-79.
Adam

 

http://www.3reef.com/forums/asap/lets-not-respond-all-once-now-52163.html