***URGENT***FoxFace has swollen stomach

[DKoKoMan]

Hey folks,

The other night I noticed my large fox face has developed a large swollen belly. He is now struggling to swim around and has no interest in eating. I have scoured the web with little to no information. Is there anything I can do to help him?

I am having a hard time catching a photo as he has now become skidish but I'm very concerned.

Anyone has this happen? This literally came out of nowhere.

150g Reef with 40g+ sump.

ALK: 9.4dkh
Cal:450ppm
NO3: 2-5ppm
PO4: 0ppm (Hanna)
Mag 1400ppm
Sal: 1.026.