It is not important to have a UV sterilizer in any set-up. There are many more mportant things to spend your money on (live rock, good filter, protein skimmer, RO/DI unit, powerheads, heaters, better test kits, refractometer) and if you you have extra money when you are done buying all of those things, then maybe think about getting a UV if you really want to spend more money on your tank.