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Totomatix is the name given to a nutritional automaton (titrator/regulator) designed in our laboratory to grow plants under controlled nutrition. In response to plant growth, the automaton regulates the nitrate content of the nutrient solutions as well as their pH and volume in the storage tanks. This device manages a maximum of 6 independent tanks, and allows (1) to measure and compensate over time the absorption of NO3 by the plants by injecting a precise volume of a concentrated nitrate solution, (2) to measure and regulate the pH by injecting an acid or a base, (3) to regulate the volume of the nutrient solutions and to measure the water added to restore the set volumes, (4) to regulate the temperature of the solutions in contact with the roots. Totomatix has an smart man-machine interface, which is composed of a measurement acquisition and control software, able to trigger alarms in case of malfunction. The software allows setting special conditions to grow the plants and to make these conditions evolve over time to elaborate innovative nutritional scenarios, for example the maintenance of very low versus high nitrate availability over long periods (months) or the transition of growth periods from high to low nitrate availability, or vice versa. This tool is totally independent of the cultural system, it can be used either on an isolated plant cultivated in a pot or on a whole culture in hydropic setups forming a plot. Totomatix has already been used in growth rooms, greenhouses and outdoors (the water orchard), in short (20 days) or very long (1 year) experiments. In these conditions, the researcher controls the time step of the measurements and the regulations. We have already used Totomatix with measuring frequencies ranging from several days to 10 minutes to study the diel variations in plant nutrition. The device is currently installed in a PSH greenhouse.