SPS bleaching

[capy]

So for a few months now i've been keeping sps in a jbj 28 gallon led all tests have been good and acros have been doing great.As of overnight yesterday my deep water yellow acro has completely bleached could this be because of anything specific or does this just happen sometimes.I also had a pink birdsnest couple weeks back that i had out of water for to long and bleached but is now making a recovery any ideas or sugestions?Thanks

 

[Dejavu]

Does the acro have any PE. If not i would guess that it didn't beach and actually RTN on you.

 

[capy]

PE meaning polyp extension? the type of acro didnt have polyps even the big colony that it came off of.

 

[capy]

its the small yellow acro to the left just above the zoas picture is bad sorry