Last Friday I lost my beautiful 4" male Square Anthias (http://www.sdreefs.com/forums/showth...Not-Doing-Well!). He had been in a quarantine tank for 2 weeks and was doing great. Suddenly, Friday morning he did not come out for his breakfast, so I knew something was wrong with him. I thought maybe the ammonia level spiked, so I did a 40% water change and hoped for the best. After coming back from work on Friday afternoon, the fish was gasping heavily and 2 hours later he was dead. I was very upset and puzzle with his lost. I kept the water parameters in check and did water changes twice a week. After a lot of thinking, I couldn't find any reason why a very healthy looking fish died in less than 24 hours. Well, after breaking the quarantine tank (I am not in the mood of adding more fish to my display tank right now), I noticed a big hole at the top of the glass meter thermometer . So likely after the thermometer broke, it released mercury into the water column killing my fish. From now on, I will only use the adhesive strips
thermometers or maybe I will just stick my finger in the water.