Please help to save my Yellow Tang ASAP

[KevinATran]

Hi,
I'm new to this forum. Hope I can get help from you guys and/or profresionals.
My tank is 50-gal corner hexagon with 15gal sump, has been set up 9 mons ago. I had many types of LPS and a couple of False Percula Clownfish. I just added a blue tang and a yellow tang last weekend. When I got up this morning, I looked at my Yellow tang. It has 2 brownish areas on both sides of its body at the center as big as a dime. They look brown in the dark and kind of red pink in light. This is the second time that I put a Yellow tang in my tank and have seen the same problem (the first one was 3 mons after I started my tank. The Tang was dead after a few days I discovered the problem. At that time, there was an ich problem in my tank. I thought that was from ich. I made 100% water change and running it for 2 mons without any fish. Then I added a couple of clownfish, which are still healthy till now). The Blue Tang seens to be ok up to now. Anyone knows what it is and how to fix it ? The parameters are Amonia = 0, nitrite = 0, Nitrate = 10ppm (as low as I can keep), Ca = 415ppm, Alk = 10.2

Any suggetions will be appriciated.

Thanks,

 

[goby2]

My tang always gets a slightly brown semi-circularspot over a white line at night. Could that be what you are seeing?

 

[KevinATran]

Thanks Goby2
What I saw was circular (not semi) spots over white lines on both sides ot its body. Did you see it on both sides or just one side? Are you able to see those spots under the light? If so, what colors are they? I didn't see them on mine when I first bought it? Do you know what causes it?

Once again, thanks.

 

[goby2]

That sounds like just the normal night time coloration. Mine has it every morning. It's just a large brown blotch over a white line in the middle of the fish.

Does it go away after you turn the lights on for a while?

 

[KevinATran]

Hi, Goby2.
Yeah, mine went away after lights on for while. I was worrying too much....

Thanks,

 

[Len]

Kevin, don't get a butterfly fish; the pigmentation change from night and day will give you a heart attack

 

[KevinATran]

Thanks, Len. I will make sure that I won't................

 

[NMreefer]

Yeah man, don't sweat it. It's natural. Well said Len. :lol: