I don't know to much about small tanks but there are those in here that do and they will chime in with their expert advice. This is what I would do if I were you: First I would read all of the stickys at the top of the saltwater section in this forum. Then I would go buy a good saltwater book for more reading. Now this is the part of "if I were you" I would try and get my money back on the tank you bought and I would try to find a small complete system for sale. People are always up grading in this hobby and also getting out of this hobby, and most of the time you can find a complete system for around $400.00. This will get you started with everything you will need, not cost alot of money in case you decide this hobby isn't for you. If you decide to go this route, before you buy, let the pros know what you are getting in the system and they can guide you a bit. I am not trying to talk you out of a small tank here (don't get me wrong, I am just saying) Saltwater is a bit differant than fresh. In saltwater the ones with the smaller tanks are usually the experts, its hard to keep a small tank. On the plus side, you want to keep fish only, that makes it a bit easier. What kind of fish do you want to keep, the smaller the tank, the less fish you can keep, will they get along with the other fish you want, will they grow to big for the tank you have. Lots to read up on. There are some pretty smart people in this forum, before you buy anything ask them first, they will get you on the right path, they did for me and I still messed up alot.