Okay so I'm frustrated as hell! I've had 2 mandarins die and now a tomini tang die in my 30 gallon cube. It's been established for over 8 months with live rock, and even some coral. I have a snowflake clown that has been in the tank from the beginning and he has never showed any signs of sickness. The tang was only about 2-3 inches, and planned on moving him over to my 300 gallon later on once he got bigger. Water parameters are as normal. Picture to show. I don't get it.