Why can't I keep Green Chromis? My tank has been around for 6+ years. I've got lots of fish-tangs, clown, wrasse, gobies, etc. I've tried them at least 4 times in different batches over the years. Last month, I got 3 and luckily one lived. The others died overnight. So at the meeting, I picked up 2 more hoping that they could be a trio again. And overnight-gone. What is the deal? Is it me or are these easy fish not so easy? I hate spending the money for 24 hours of "chromis" watching...they are so pretty. Poor things.