Pale Coral Beauty

[drm]

Hello all-
I have recently upgraded from a 30 gal tank to 100 gal. In that main tank, all is well.
I had 2 fish which died prior to the upgrade
-one (Coral Beauty) when I was on vacation and there was a little problem... but had lived more than a year before that.
-a second (percula clown) got sick after I tried to add another clown, to replace the coral beauty... I quarantined the new fish, but not for long enough.

So, I now have no fish in main tank, just lots of inverts and come corals. New coral beauty is in quarantine. Today is day 8. I find quarantine very stressful, but I'm going to try to keep her there for 4 weeks.
She was doing great, eating well, active... yesterday evening I noticed when I got home that her body (particularly in the front, and the fins closest to the body) was very, very pale. Also, her gills looked somehow, just a little more "noticeable", which may have only been because she was so pale?
She definitely looked better after about 30 minutes or so, but I'm not sure that she had her full color back. There was a slight temperature drop, from 80 to 76 or 77, due to a brief power outtage just prior to this pale episode.
So then 4 am I get up and the power is out again, not sure why, but only for 5 minutes, so no temperature change. I went to check the tank, temp is normal, coral beauty again looks extremely pale. Gills look a little prominent, maybe a little bit red? Now, 20 minutes later, her color is again normal, she is swimming normally, seems to be OK. Maybe her gills are a bit more red than normal still.
I do not notice any fast breathing or other symptoms. No white spots etc.
QT tank parameters are ph 8.1, T 80, Amm 0.25, N-ite 0, N-ate 0, Sal 1.023.
Any thoughts? Thanks.

[melosu58]

.25 ammonia in a small QT is pretty high. I would do some daily PWC to lower the ammonia. I believe that this is the problem and that if you dont do them you might have a casulty. Good Luck.

[drm]

I have been doing 20% water changes daily, have also added Kordon's Amquel Plus, which I believe makes the ammonia non-toxic but may still cause a positive test reading. There is a chunk of live rock in there as well. So I'm doing my best to keep the ammonia down. Not sure what else to do for that.
This afternoon she looks absolutely great.
Is there any chance that this color change is something that just happens at night when all is dark? I never noticed it on my previous coral beauty, but she was usually behind a rock when the lights came on.

[melosu58]

Could be. They do get paler at night but when lights come on they become vivid.

[drm]

This morning when I went in, she seemed to have normal color, very active, all is well. I guess I will keep watching her and see what happens. Thanks.