Yellow Tang Has red blotches?????

[mrcoberg]

I searched the books and saw some treatment options but, not exactly the symptoms my yellow tang has. I noticed 2 days ago large bright red blotches on both sides of the tail area and red line right below the upper fin. I did testing the only thing I saw that was high was the nitrates. I did a 25% water change after I took a reading of 25ppm on the Nitrates. I also cleaned the simmer and set it to skim wetter to pick up a little more than normal. I cleaned the bioreactor filter screen. I went to LFS and bought lots of live brine shrimp and dosed with vita marine C and add a pinch of Spirulina 3 X a day. I did noticed the red is fading a little today. Are there any other treatment’s or id of the illness my tang has? Thank’s in advance for any feedback…

 

[TrialandError]

Possibly another water change.

 

[Reefing Madness]

Fish sometimes acquire what is loosely referred to as septicemia. Due to poor water quality.
Clean up the water and your more than likely going to be in good shape.