The Jaubert method does NOT use an overflow nor does it have a reservior below the aquarium. Dr. Jaubert, of the Monaco Aquarium, promotes a variation of the Lee Chin Eng system which uses the 'natural' approach. The main variation is the introduction of a Plenum at the bottom of the tank.
A plenum is a gap or void space underneath the one to four inches of live sand at the bottom of the tank. Typically this void space is 1 inch deep and this area becomes anoxic, or an area low in oxygen. This anoxic area creates a 'ying-yang' enviroment where oxygen strarved organisms breakdown or remove components from the oxygen carrying organisms and components. The natural reduction of Nitrate ( NO3 ) in these systems is the direct result of a plenum as it generates a 'de-nitrification' process that robs the nitrate complex of its oxygen. Another benifit of the two opposing enviroments is the natural dissolution of calcium, magnesium, and strontium to natural levels within the aquarium.
The Jaubert system does not use a protien skimmer as the removal of organics via skimmer would decrease the effectiveness of the plenum. Additionally the only water movement within the tank is that of an airstone and its resulting rising bubbles.
Placed upon the sand bottom is the live rock. The live rock should be strategically positioned so that minimizes the amount of sand that it actually covers, as the covered spots would quickly cause dead areas within the sand that it sits upon.