Purple Montipora

I have noticed some white blotches on the back side of the monti. I have had him now at least 8 months so I am pretty sure there is no Nudis. Is this normal for this Monti species. I have noticed a lot of growth which is good. He is about 14 inches under a 150 watt 20,000K MH bulb

 

have you added any new montis?? looks like nudis to me

 

If it was nudis they would have eaten the coral by now. I add last month a little monti frag.

 

if there were eggs on the new monti?? I dunno. That was just my first thought. This is the way it went when I had my bout with monti eating nudis

 

If it was nudis they would have eaten the coral by now. I add last month a little monti frag. A few months ago i cut out a piece that looked white on the inside. SHould the opposite side of this MOnti look like the inside?

 

I think it has had the white blotchiness before the new Monti frag. Is their anything else that can make it look like this?