All good advice from everyone. I'd like to add go to your local marine fish stores. Some have nano tanks set up with live animals so you can see whats possible in a small tank. Seeing is the best way to get an idea of what's possible. First rule. Never use tap water to make your salt water. Second rule. Saltwater will support much less life that a freshwater tank so don't overstock it. Third rule. It can take six or more weeks to cycle a tank before it's ready to add animals. A year to be able to keep challenging animals. Stability is rule. Don't let much water evaporate before topping up. Don't let temperature vary more than a few degrees, less if possible. Water flow is critical. The ocean is swaying animals back and forth constantly and they need good flow in your tank to bring nutrients and get rid of waste. Overshoot it on filters. You want to have a filter rated for several times your tank volume. The rock you add will be important in maintaining your water quality. Have enough of good quality rock. Now research until you have enough answers to feel comfortable.

