The pumps had a variable speed drive able to regulate the flow between 20 and 120% of its capacity. The maximum flow at 120% means 32 m 3 /h of pumped salts. The pumps used in each tank were vertical centrifuge ones with extended axis. This concept allowed the pump to be installed at the top of the tank and the pumping to be by aspiration from the bottom part of the tank, taking advantage at best of the volume of the tanks and mixing the salts with the turbulence created.