Reef tank with only skimmer and circulation?

[Ram]

I know its possible to run a setup with no power filter, sump, etc and just run a protein skimmer and some circulation pumps.

My question is do I need to add a minimum amount of live rock and sand to achieve this or is it even necessary to have "live" anything to keep the tank healthy and running with fish?

Is that all there is to it or do you recommend doing anything else in conjunction?
Thanks!

 

[Reefing Madness]

You need something that will maintain bacteria for eating up ammonia and nitrites, if you do not, then your tank will be hard to maintain.

 

[Harold Green]

It's possible to do with strictly water changes but it would take large amounts frequently to keep up with fish. The live rock and sand will remove ammonia and nitrite from the water with water changes removing the nitrates. How much you need depends on tank size, bio load(number and size of fish and inverts), amount of food you add.Most sites recommend one or two pounds of live rock per gallon of water as a minimum. A lot depends on the density of the rock. Porous rock will work better and actually may remove some nitrate over time. As far as sand goes hobbyists go from bare bottom all the way to deep sand beds(5+inches deep). A half inch layer on the bottom will provide some filtering and still be easy to clean. I prefer the courser sand over the very fine as the fine has a tendency to blow around in the current or seal up on the bottom.