My first death... : (

I am sad to report that I've had my first loss of a fish, a newly introduced Coral Beauty.

Here are a few of the details.
12-3 > Tank established and all going well since then. Water parameters good.

12-27 > Added 2 Clowns. Doing great!

1-18 > Water Tested, same good parameters
Salinity = 1.024
Ammonia = 0
Nitrite = 0
Nitrate = 0
PH = 8.2
Calcium = 480
Phospherous = 0
KH = 7

1-20 > Added Coral Beauty
Followed LiveAquaria acclimation. All went well. Seemed healthy, but shy

1-21 > Water tested
Salinity = 1.024
Ammonia = 0
Nitrite = 0
Nitrate = 0
PH = 8.2
Calcium = 460
Phospherous = 0
KH = 7

1-22 > Weekly 10% water change. First time using LFS water. Tested water before using and all parameters were good. Same as my water.

1-23 > Coral Beauty still shy and not eating, but still seemed healthy

1-24 > In the morning, Coral Beauty seemed to be breathing heavy and hiding in a LR cave, but visible. By nightfall, dead.

1-25 > Water tested
Salinity = 1.024
Ammonia = 0
Nitrite = 0
Nitrate = 0
PH = 8.2
Calcium = 480
Phospherous = 0
KH = 7

Really not sure what happened. Everything seems to be going well. The 2 clowns are very health and happy. All of the clean up crew are doing well. The only thing that was different was the water from the water change, but since the parameters were the same as mine, and all of the other livestock is doing well, I don't think that was an issue. The Coral Beauty wasn't eating. Maybe sick from the beginning, but didn't seem like it.

Any ideas or things I'm missing? :help::confused::bawling: