Joes Golden Dragon tissue loss

[tidefanjam]

I picked up this frag about a month ago along with a Milli and a birthday cake acro, my tanks been up 20 months and these are my first 3 acros and they are doing well with good pe along with coloring back up well, the Golden Dragon took the longest but has colored up well except for one stem which has been losing flesh, it’s been the same for a while and doesn’t appear to be spreading, what could this be? Should it get better on its own?
Nitrate 4
Phos 0
Temp 77.4
Calcium 420
Mag 1320
Salinity 1.025
Ph 7.9
Alk 8.3

 

[SOCOM]

Balance out phosphate. What par is it at?

 

[tidefanjam]

Balance out phosphate. What par is it at?

I’m not sure about the par, don’t have a meter, I have it in a partly shaded area on the edge of the rockwork, my understanding is that it’s a deep water coral, I do need to get my phosphate up, I’m currently treating with Fluconazole for bryopsis, but the tissue loss was there before I started.

 

[SOCOM]

Get phos up which will stop the loss to .08 ish. Par to establish base. Send me a PM, I have a potion for no3 and po4 for you. I'll get you right.