Bleached patches on my plating months?

[LesPoissons]

Hey guys I have probably 20-ish species of lps and sps in my 220. Everything is looking great except my 2 plating montis just on one side of the tank that have bleached patches. They are in areas that can’t be touched by any other coral. Is this common? Thoughts?

 

[jeffchapok]

I'm guessing they were hit by a member of your CUC. Got any urchins?

 

[jp_75]

Nudis?

 

[LesPoissons]

Hmm... I do have a pencil urchin but he didn’t get on the green one bc it’s loose and would definitely topple if he went on the edge of it. I’ve had the corals for about 4 years and I dip any new ones but maybe a nudibranch got through on something else? Can they survive coral dip?
The rest of the cuc is hermits snails and I think a serpent start still lurks somewhere.

 

[LesPoissons]

Do the montipora eating nudibranch stay on the coral or move off during the day etc? I’ll see if I can spot anything.

 

[HB AL]

Look under the coral for nudis when the lights are on that’s where they will hang out. if no other coral is stinging it’s very possible it’s nudis especially since the issue is on the ends and not in the middle of the caps.

 

[LesPoissons]

Argh. I swear- everything is finally balanced and great and something new always pops up that ive never heard of. lol. Gotta love reefing! Thank you!