The puzzling thing to me is that part of the live additions die and the rest are thriving. (1) Addition of four green chromis...died after a week, one at a time. I think this was my handling or the tank, not the fish. (2) Death of one of two clownfish after two days...other clownfish is fine to date, more than three weeks later. I suspect something was wrong with one of the fish. (3) Death of sailfin tang within 4 hrs. This fish was never active, became more inactive and then died. I think the fish had a problem and the fish store did issue a credit. The other clownfish, firefish goby, and cleaner shrimp added at the same time were fine and continue to thrive. (4) Red grape tree on rock not surviving. Red grape tree (same shipment, but stuck under a ledge) is OK. (5) Red tree sponge seems fine after nearly a month. (6) All snails and crabs are thriving (but I know they are hardy). My nitrates haven't run zero yet. My salinity is stable and I change 15% water weekly and run the lights only two to four hours a day. I've created a quarantine tank into which I would add any new fish. I've tried a new source of fish. I'm watching and waiting for the tank to show zero nitrates. Basically my budgetary constraints make it very easy for me to go slowly.