I've had my 100 gallon running for 8 weeks now. About a month ago I added 2 damsels and some fully cured liverock and "real" livesand from LFS
. Last week I added a small tank raised percula clown. He was really happy and active and the damsels seemed to ignore him. I fed them a tiny amount before I went to bed last night and I watched him eat. This morning he was swimming around normally and actively. Went home for lunch and he was laying on the sand dead.
Not sure what caused his demise. Tank parameters seem to be acceptable. I do know that sometimes fish die and the reasons are elusive. Last night, before his death I sort of seem to notice some very tiny white spots on him. Ich maybe? But even if it was Ich his death seemed rather fast.