Boy, alot of people have misconceptions about marine tanks. A marine tank is no more complex than a fw tank, doesn't need anymore support equipment. The only difference is salt. It is only if you start into having lots of live rock and invertebrates and corals and stuff that you need more support equipment. I kept a 10 gallon native goby tank for years with undergravel filtration powered by an air pump. Worked great, they even spawned, but I never tried to rear the larvae, as the full grown fish are like an inch long.
But, lets not high jack this thread, lets keep it on the op's question. If you have questions about SW, check the SW forum, or PM me.