Yellow Tang/New Tank

[Speedmonster]

New to the saltwater hobby, so hopefully will find an answer here. I have had my tank for about 3 months running now and have been checking water quality weekly. I added 2 clowns which have been doing well for over a month now, and just picked up a yellow tang from my lfs earlier than I wanted due to the shortage. I just got back from work tonight and noticed the tang had big dark spots on both sides right in the middle of it. Is that just food or something more? I've only had it for 5 days now and this is the first it's shown up

 

[MaxTremors]

Looks like stress coloration. Tangs will get darker or get dark patches (or lighter patches) when stressed or upset and they also sometimes get it at night. Should go away (sometimes in a matter of seconds). If all other behavior is normal and there are no other signs of disease, I’d guess it’s stress coloration.

 

[Uncle99]

What were the results of your water quality test?

 

[Speedmonster]

What were the results of your water quality test?

0 ammonia, 0 Nitrites, and 20-40 ppm Nitrates. Been like this since I cycled the tank (3 months)

 

[LiamPM]

Its just its night time coloration

Nothing to worry about and will go back to what youd expec twhne the lights are back on.

Most fish have a change in colour one way or another when it becomes nighttime to them.