Depending on how young your tank is, it might still be cycling. If it is still young, give it a couple of months to settle down.
Regular water changes will take care of some nitrates, the addition of a protein skimmer will also strip the water of nusances. Make sure that you don't have any sponge filters or anything. Those are nitrate traps.
Growing macroalgae in your refugium would also help keep the nitrates down. Get some mangroves, those are pretty neat. (some say that they don't pull much phosphate out of the water, but I think they do, by my experience.)
Have fun!