Monti cap bleached completely overnite....
 

It was a nice green one I have had about 3 months about 3"X3". Had a temp drop overnite of about 5 degrees ( didn't realize my heater isn't working properly ) . Color was stark white this morning :eek2:. All the polyps are closed. All other corals- zoas, leathers even other caps are fine. No other changes in tank.:spin3: Need to ask the experienced sps crowd....was it likely the temp change and are there any chances of recovery. Temp was down to about 73/74 degrees. Any input truly appreciated! :spin3:

Hard to say. I have left my heater off by accident and gone from 80 to 73 overnight and my monti was fine. Coral are fickle though....

It's very disappointing and happened so quick!

If nothing else changed the drop in temp was the most likely cause.

I'm going to say it was not the temp drop. I've also never heard of a coral bleaching overnight. Are you sure it didn't RTN?

What's your alk/pH at?

Agree. What is your alk? I have seen Montis bleach with low alk.

I also think that is wasnt the temp drop that is not that extreme unless it got lower than that. It has to be something with your water what are the parameters?

I will test everything in the morning. It was sudden- truly. I am in front of the tank...it is only a 55- with a magnifying glass almost every nite. I love checking out all the little critters! Color was great last nite! Could someone tell me a little more about rtn. Nothing else including my other Monti Caps was affected.... thansk so much for everyones input!

Also, I'd think this was not because of the temp swing. How does the temp usually fluctuate anyways.

RTN is due to... well, not really sure. Some say disease, others say stress. Alk issues would be a problem, as I know high alk will cause STN.

RTN is where the coral literally melts away. The tissue just falls off it.