Tangs Unknown Condition

[ssandalson]

I have two tangs - a yellow and a purple in a 75g FO tank. I have noticed recently that both look sick in their own ways.
The yellow tang has some red spots on his body in varying places and the purple tang has some discoloration along its back under the fin.
Any ideas? 50% water change done last week does not seem to have helped. Both are still very social and eating well. All levels are normal - salinity 1.023, PH 8, Amonia 0, nitrates and nitrites at 0.
I am going to try to attach a picture of each.
Please help.

 

[smokinstarfish]

Why would you do a 50% water change?

 

[ssandalson]

Cant seem to attach a picture - telling me the picture size is to large - not sure how to fix that problem.
I had read (on another tang post with similar condition) that a large water change might help with their conditions and that this would be the first thing to try.

 

[bdhough]

Smokin a water change big or small is a good place to start with sick fish. Helps to "freshen" the water.
ssandalson you have some very very sick fish or soon to be. The first is like ich but something else. The second sounds like the beginnings of head and lateral line erosion disease. Both are treatable but also deadly. Sounds like you caught them early. If they ever stop eating then i would start to worry. Do a search on HLLE and make a new post named yellow tang with red spots. Youll get more responses on that. I don't know what its called. I want to say brooknellya but im not sure

 

[bdhough]

JW knows what he's doing
btw is the red tiny spots or patches of skin that are reddish?

 

[beth]

Make the pic smaller until you can post them so we can see what the problem is.

 

[ssandalson]

Trying to send a picture again - this is the purple tang - hope it works.

 

[ssandalson]

Here is the yellow tang - seems as if last night I was just too tired to figure out this picture thing.
Thanks for all the help everyone.

 

[beth]

Did you raise the pH? What are you feeding these tangs? Do you have a grounding probe installed?

 

[bang guy]

The Purple just looks slightly stressed. The Yellow is in very bad shape.
Having two Zebrasoma Tangs in a 4 foot tank is a really bad idea. I would guess they are stressed being so close and the Yellow is losing.
Try to find a new home for the Yellow before it's too late.

 

[ssandalson]

The PH after testing today is 8.2. I feed them seaweed, formula one flake, and frozen brine. Do not know what a grounding probe is.
I have had both of these Tangs in my tank for over 6 months and they get along great and I have not had any problems up until now.
The yellow tang is actually looking a little better today. Both are very active and eating very well.
Any suggestions?