Ive currently got a 90gal freshwater that I love, but sense Ive joined AA, Ive been extremely jealous of every ones BEAUTIFUL saltwater tanks. This may be a few months down the road, before I even buy the tank, but I figured I would ask advice from successful saltwater tank owners. I was thinking of having a 20-30 gallon with a couple puffer fish. (they are so adorable!) Ive been told by several friends that have tried a saltwater tank, that it is extremely hard to keep the fish alive. Any advice, or secrets?