Hey Mark, I think the definition is in cycler's sig.
cycler, I'm running my reef like this, but I've never really researched it as a method. I guess after reading enough about people being able to run their tanks without skimmers, I decided to take mine offline. I replaced the old cramped wet/dry sump with a nice big open sump that is entirely a rock, sand and macroalgae fuge, with only the heater and auto topoff as intruding equipment.
So, I guess you would consider my system to be running "balanced"? I have had no filters or skimmers on the system since I did a complete overhaul on it 2 years ago. That's not to say that there is no "filtration". I have TONS of macro algae growing- some of which I throw away occasionally, and my not-so-deep sandbeds are filling up with gunk -especially in the sump where I've got some really black spots against the glass. Another thing to keep in mind is that I am not keeping very demanding SPS yet, but so far, everything I have is thriving!
The only tests I've done in the last 2 years were using a TDS meter on my RODI water (THE most important test IMHO), and checking the salinity with a swingarm.
Is this what you mean, cycler?