Conditions characteristics A) Spectral composition of visible light produced by the illumination sources used in this study. The graph is based on data provided by manufacturers and normalized to the same total visible light output. B) and C) show PAR intensity measured in both axes of the shelf at a distance of 40 cm from the light source. Data points from one of the three technical replicates are shown. The datapoints represent the average from three measurements. Standard deviations were within 2% of measured values. D) Total water consumption after one month of the different plant species. A. thaliana tray contains 24 pots/plants with jiffy tablets. It was made in three biological replicates. Error bars represent SD. Asterisks indicate statistically significant differences compared to plants grown under fluorescent lights (** P < 0.01, two tailed Student’s t-test).