Supposedly there is a filtration system[nitrafier] that not only eats nitrates, but it also allows you to not do water changes anymore. I hit the website that sold that resently, but don't remember what it was. Probably if you brouse for nitrafying systems, or look up nitrate control on About.com, you can find what I'm talking about....it didsn't look like the easyest thing to setup, but if you're going with a new setup, I'd probably give it serious consideration.
Additionally, there is some new "natural" work being done where a separate "sump" is setup, but instead of equiptment you put in sump you grow macro algae and mangroves. These plants eat the nitrate. Basically, though, you are managing 2 systems then...your aquarium with fish, reef, and your aquarium [usually under tank] with plantlife....both requiring care and attention [not to mention $$$$ to maintain].
