I need some HELP asap..

[Sabellafella]

I have a small piece of cyphastrea. But I don't think it's pictured? Which pic are you looking at?

it looks to be either bacteria or flatworm related. Theres not 1 sign of bleaching coralline algae in your tank so im pretty positive its not water quality.I had bad dieoff outbreaks just from changing fishfood and magnets rusting. I also had a problem happen like this from overdosing aminos that effected nearly all my staghorns and validas with that black band disease. I couldnt figure out what it was, but after dips in iodine and adding a couple pieces if liverock fixed it for me. I wouldnt sweat it, stuff like this happens and the hobby will push your limit at some point. Just dip everything once a week and frag atleast 1 part if healthy tissue just incase the coral passes. Give it some time and then more forward. Theres so much uncertainty in this hobby, its a never ending battle to figure out why stuff like this happens.

 

[scfurse77]

Update: thanks @Sabellafella for the help. Stuff is improving quicker than I thought. Not sure what it was that I did to fix it. But I think it was a combo of things.

Lowering my nitrates to below 5 with NOPOX

Cranking my lights up slowly to almost double what they were when I thought I was bleaching coral.

Made a mixture of AC/Rowa in the reactor.

Big thing was trimming off dead parts of coral to help stop the dying. Thanks again @Sabellafella for this tip.

Here is some pics that to show the progress of the SPS.