Keep in mind if you do SW it will be a lot more putzy than freshwater. You can't just attach a hose to the sink for water changes, you can't just dump new fish in and expect them to live. Quarantine is absolutely essential and never buy fish from Petco unless you plan to quarantine for a couple months. I used to have SW but I sold it because I got sick of all the details; that said I felt it was something I had to get out of my system... I get tempted to go back whenever I see marine fish though. I have decided if I am ever "rich" (whatever that means) I will try Saltwater again, and buy all the nice equipment this time to make everything easier. I would especially make sure you make/buy a good automatic topoff.