Hey guys,
I'm relatively new to the saltwater reef industry. It seems I have become obsessed with creating an ecosystem that is self-sustaining. I'm here in Salt Lake City, Utah.
If your really set upon this, get yourself a copy of the book
Dynamic Aquaria, Building Living Ecosystems by Adey and Loveland. This describes such systems in great detail. These systems tend to be large and complex because you need to consider building something that takes into account the entire food chain from bacteria to whatever you want to keep. They also tricky to maintain. If something goes a little wrong, it's going to need a lot of intervention on your part to fix the issue. At that point, it's really no longer "self-sustaining".
I'd put these type of systems at the level of expert only, and in the realm of more or less experimental systems. Can they be done? Yes they can, but chances of success by someone new to the hobby is very low.
At this point, I recommend you set up a more conventional SW aquarium, and see just how tough that can be, and then later on consider building an "ecosystem that is self-sustaining".