alot more than just that. you will need a light, esp. if you want coral. you might be able to get away with a pair of clowns. you don't really want gravel in a Salt. you want sand or crushed shells. you'll need live rock about 15 lbs should do the trick. depending on what the "filter" is you are referring too, you probably dont need it if it is a carbon filter, will do more harm than good. but if you have a protein skimmer then it is probably un necisarry. you'll need salt mix, R/O water. you'll need a circulation pump. well two circulation pumps and another heater, one for the main tank, and one for the saltwater mixing. With a 10 g. you will need to do constant water changes and alot of maintenance because salt water fish are very intolerant to water peram fluctuation. If you do decide to go with this i hope you post many many pictures! i love nano tanks XD