A hydroponic growing system comprising an elongated trough. The trough (10) comprises at least a first side wall (34), an opposite second side wall (36), and a bottom wall (60), which all extend in the longitudinal direction of the trough and delimit a space in the centre of the trough, open at the top. The trough (10) also comprises a partition wall structure (20) extending in the longitudinal direction of the trough and dividing said central space into two adjacent elongated grooves (12, 14) which are open at the top and into which one or more substrates (74, 76) can be placed for the cultivation of plants (72). In an example, the partition wall structure (20) comprises an elongated overflow channel (22) extending in the longitudinal direction of the groove (10) and guides the irrigation water past the grooves (12, 14). The overflow channel (22) may be arranged in an elevated position with respect to the bottom wall (60).
