Ive got a 55 custom half moon reef tank established about a year. Every couple months a fish just stops eating for a couple days and then it dies. No sign of disease or parasites. Needless to say this is very discouraging. All tests look great. I'm wondering if I should treat the tank with some meds but I don't know what to treat for and I've read its not good treat a tank if you don't know what's the problem. What meds are reef safe? Any help and advice is highly appreciated!