I was recently thinking about converting either my 20 gallon, 29 gallon or 55 gallon fw tanks into Sw. In my school science room they have a 29 and a 55 sw tank set up, but all it is is a heater, sw, a hang on filter and about 10 punds of live rock. Could someone point me in the direction of a cheap efficient set up, as i am only 16, that would work well and i could slowly add stuff to it? Thanks for your time and effort, Chuck.