Each system included twelve 0.15-m3 circular tanks (microcosms) with a bottom area of 0.5-m2 diameter, supplied by intense individual aeration with air stones.
Each experimental tank was associated with water input pumped from a matrix tank (4 m3 each), referred to as macrocosm.
In each system, a submersible pump distributed water to the tanks, and this water was returned via gravity to a drain directed to the macrocosm tanks. In both systems, the water was completely recirculated from the macrocosm to the microcosm ≈20 times each day (flowrate ≈ 2.1 L/min/tank).