I have never seen a proper set up reef tank have any nitrates.. I have seen phosphat problems though..

Steve

As usual I'm going to go against popular opinion, I myself like fluidized bed filters. My experience however is ONLY in fresh water but it's been something that I am planning on for a project I've got in my dreams. Fluidized bed in my opinion is a great filter as it allows bacteria to grow but not build up on the particles. It responds quickly to density changes (tank population density) and can help when you are running a breeding program. As far as marine systems go I believe it's another way to add filtration and if you have a small crash of sorts it may be just the ticket to help you save some of your livestock. YES if your power goes out it's not going to help but, a battery operated air pump plumbed in would keep things alive for a period of time maybe....

Doug