Using filter media, socks is an economical and effective way to control your nitrate and phosphate input; however, swapping/cleaning them and how often to do so is personal view/choice (like @SepToob mentioned above)...
If you go with reeftopia.com, please add 12 cerith snails ($15), sea urchin, pincushion - L. variegatus (4 Lot - $32), and shaving brush plant - Penicilus sp. (3 Lot - $12)