SOS for my SPS

[Tray333]

This is day two of what appears to be bleaching of my descending acro. What parameters all in specs except phosphate which is .16 per Hanna checker, and no detectable nitrates with API test kit. Some of my zoas previously have been melting away in the last two weeks before this happened.
Sal. .26
Ammonia 0
Nitrates 0
Mag 1410
Cal 420
Carbonate hardness 9
Ph 8.2
Temp 78 f
Nitrite 0
Running Gfo reactor, protein skimmer, chemipure elite , Red Sea 250 max 66 gal. Dosing 2 part @ 6 mil a day. Fuel, reef roofs, oyster feast, roe, reef frenzy cocktail, my sis coctail 2 times a week. Most other coral look ok, assortment of softies, sps, lps, with six reef fish. I did 20 percent w/c 4 days ago. Any guidance would be appreciated.

 

[Tray333]

Salinity is 1.026

 

[ReeferMadness80G]

Sorry I had to reread your post! Is the flesh coming off the sps? Or is the flesh turning white? I am still a little concerned about 0 No3. How long has the sps been declining? Do you have any other corals in close proximity? What are they? What kind of fish do you have? And what kind of lights? How high are they off the water?

 

[Gargamell]

Nitrates do seem low, how many fish are in the system and I would frag the dead parts off

 

[luke33]

That's a lot of feeding there! Probably why the phos are so high. How old is the tank and are you using rodi water?

 

[joseserrano]

make sure you are following the steps exactly for the api test kit (and all really), you will get way different results if you half butt it.

 

[Tray333]

Yes I get water from lfs that I check with Hana before introducing water changes. Tank is almost year old.
5 fish maroon clown, file fish, yellow tank, 6 line wrasse, and cardinal.
Yes the flesh is coming off the sps. From top to bottom. And then Skelton bleach.

 

[Monkeytank]

Cut off the good part and you may be able to save it. If you wait, it will all just die. I've saved frags and regrown the colony like that before.

 

[Tray333]

2 hd 52's at 40 percent acro is about 6 inches from top of light. But it has always been there.

 

[ReeferMadness80G]

Is there anything new recently you've done it added to the tank? Any swings in temp, or alkalinity? Check for rust around anything wet, doubtful due to the age of your tank, but still check. Change in flow or lighting schedule or anything? Keep an eye on it for fish nipping at it. Blow it off with a turkey baster or syringe and see if any bugs fly off. RTN can really be a lot of different things combined. Don't make any quick changes, it's not worth risking all your corals to save one.

 

[Tray333]

Ok thank to all, I took the advice and cut the dead part away from the colony and lowered it midway in tank. As I put the live part back in it started sliming strings out of it. I hope I can safe it. Again thanks to all.