white spots on green montipora

[sharonbm76]

I bought 2 month ago green montipora, it grow for few weeks and I notice last week that I have some white spots on it.
what do you think it is?? this morning I took it out ant dip it with coralrx for 10 minutes and put it again in the tank.
thank!

water parameters:
nitrate 0
phosphate 0
alk 7.5
calc 420

 

[sharonbm76]

:wave:

 

[CJ 1098]

Hard to tell from that pic.
Try using photobucket to post pics and they will be bigger and more clear.