To Frag or not to frag....dinoflagellate attack

I moved this birdsnest on the sand just for this picture, this is not where it usually is!

I have been batteling what I thought was just cyano for a couple months or so. Started out mild but has progressively gotten worse with it really getting bad yesterday!

My parems are: pH 8, kH 9, ca 500, ammonia nitrate phosphates and nitrites are neg,
I dose 2 part daily

I had reduced the photoperiod in my tank, added a phosban and carbon reactor, increased the flow (flow is about 6300gph in a 135 tank and just added another koralia pump within a couple weeks), decreased feedings by over half,doing manual removal daily if not 2x a day, doing weekly water changes, have a fuge with cheato...whatever possible I tried.

Well yesterday I noticed that the stuff that was once mainly on my sand and a little on my rocks is now all over my corals. I cleaned off my corals and noted that a few of them are looking very puny and this birdsnest is dying.

I am careful at examining my corals and fish daily and there was no sign of this occuring until a couple days ago. So with a friend have decided it is dinoflagellates (AW CRAP )

I have turned off the lights all together, trying to slowly increase the pH above 8.4, manual removal etc....

However this birdsnest is looking worse each day! Yesterday it had much more polyps on it....should I frag it and try to save the green part, leave it alone, or toss it out. It does not appear to be RTN to me...but I dont know. It is brown and not white.

Any suggestions

 

What is the stuff that looks like little flat leaves on the coral ?with not any white light its hard to see the true coloration of the coral.. Maybe just bleaching or some pest is eating it ? look it over well with a magnifying glass
The brown could be just the RTN areas that have been overgrown with algae or it could be a sign of disease as-well but the lighting color makes it hard to see or say for sure.