Back in 2003, I wrote a column about saltwater aquariums, specifically about keeping clown fish. The movie “Finding Nemo” had just been released and children wanted their own little Nemo. At the time, ...

Cultivating a saltwater fish tank is a bit like making a souffle — impressive if you pull it off, but delicate and easy to screw up. Still, it's easy to see why this hobby remains popular. At its best ...