deaths

I am fairly new to reef keeping I have been searching like mad for answers I picked up 2 Bangai Cardinals over a week ago to add to my reef and they seemed fine but then out of nowhere one of them went like a dark grey n was struggling to swim I found him wedged under my live rock so I rescued...

Okay, I may know some of you, i haven't been on in a REAL long time. I have a 20g nano with around 30lbs of live rock and a 1" sand bed (i think " is an inch, correct me if im wrong xP) I can say im only 13 and I get PREETTTYY angry sometimes. But, what im about to tell you is what gets me...