Please explain the unexplainable (at least for me).
Many of you are probably aware of my earlier posts about my tank a few months back. At this time, the tank is about 4 months old and has a mixture of corals (soft) and fish. All the corals are thriving and there are purple algea appearing everywhere. Nitrate = almost zero, Nitrite=0, Ammonia=0 and Ph=8, calcium=375. Last week, one of my green chromis disappeared and presumed dead. All 5 other chromis are thriving. Last week I bought a salfin tank that has been dealer tank for two weeks. He came home and after a few days quarrel with my YT, they got along well by staying out of each other' way. This morning, he is no where to be found and after much looking, I saw him sulking behind the rocks. Just last night he was out and eating and looking fine. I checked water chemistry and it is fine. I am sure he will be dead when I get home tonight. What is the probably cause for the dead of the chromis and the poor state with the Salfin tang?
Tank=125, ref,sump,protein skimmer.
Fish= YT, 5 green chromis, 2 cardinals, yellow blenny, 2 tomato clowns, salfin tang.
Thank you. Dai Phan