Red blotches on tang

[MalteseOne]

I was gone a week and noticed this on my return.

we switched to new frozen food in same time frame because petco was out of what we normally used.

Please help me identify what it is so I can treat my tang. He is looking sad, extra scared of things, and red blotches

 

[Skynyrd Fish]

When is the last time you added anything new to the tank?

 

[MalteseOne]

When is the last time you added anything new to the tank?

Have not added anything for nearly 90 days or more

 

[MalteseOne]

Well, I did nothing and he is still alive. At one point he was with giant red rings, long lateral red stripes, and more, then it started slowly getting better. He still has red rings but now I think another fish is getting ill.

 

[Wen]

I’m sorry no one offered advice here.
Updated photo? Looks like a treatable bacterial infection.
@Jay Hemdal

 

[Jay Hemdal]

Well, I did nothing and he is still alive. At one point he was with giant red rings, long lateral red stripes, and more, then it started slowly getting better. He still has red rings but now I think another fish is getting ill.

Can you post a new picture of the tang, and then give us more information about the new fish that you think is getting sick? The link below my name here gives some hints as to information that helps for us to have.
Jay

 

[MalteseOne]

It's ok, and I'm sorry for late reply, I kinda have up hoping to get advice.

The fish I mentioned had gotten worse. Basically, I think it is tail rot on a clown. Now it is 2 clowns. But I should mention I think it is related to the fact that the larger more established clown has been harassing the small clowns.

The reason I think it is related to stress caused tail rot, is because the small clowns did the exact same thing to a single clown months ago.

My solution will be to get rid of my old larger clown and hope the smaller clowns live. I won't do a hospital tank because I always seem to move a fish, try hard and it dies anyways.

As far as the tang, it went from full healthy yellow to literally fully half of the fish being bright red. Large lateral lines and two large circles were the most persistent patterns. I wonder if it was from the tang eating cyano during my outbreak (nearly solved by chemiclean) .

Overall my water is still under a year old. Old rock still releasing phosphates which I finally might have on the decrease after first change of gfo.
Ammonia 0
Nitrites 0
Nitrates 10
Alkalinity 7.8dkh
Phosphates 400 (.131 *3.066 on ulr meter)
Ph 8.34 (trying to lower it slowly since it went up)
Temperature controlled to 77f
Salinity 35

Fish and mushrooms in my tank. Lots of dinos too .

 

[Jay Hemdal]

"Tail rot" in clownfish is almost always caused by aggression from another fish - then the damaged fins get infected with bacteria. If the infection is minor, simply isolating the fish will take care of the problem. If the infection is moderate, you would also need to dose with a broad spectrum, gram negative antibiotic like Neoplex or Furan-2

The yellow tang has classic septicemia that this species shows. I don't know the root cause(s) for this. It sometimes goes away on its own. In other cases, the treatment would be with antibiotics as well.

Again, if you can post fresh pictures, it would help a lot....

Jay