Apparently, it all comes down to luck when keeping Blue-Green Chromis. First-time saltwater tank owners want an easy-to-care-for fish to start their collection. So, when I asked my local fish store guy which type of fish he would recommend for a beginner with a 90 gallon tank, I was immediately directed to the Blue-Green Chromis (Chromis viridis). These fish are inexpensive (I paid $4.00 each) and have remarkable coloration where the blue blends into the green, creating a shimmer effect. This really stands out, especially when you buy a school of them. They are pretty hardy and can tolerate fluctuations in water quality that commonly occur in beginner tanks. Blue-Green Chromis are listed as peaceful, community fish that will swim openly around the tank. I purchased five. For the first month, everything was peachy in my tank. The Chromis investigated the entire aquascape as a group MORE: The Chromis Wars