A feeding system (5) for a closed pen (1) for fish farming, the closed pen (1) being provided with a water-supply system (3) comprising a supply pipe (31) which, at its upper portion (39), is provided with a housing (6) with a lower portion (60), a middle portion (65) and an upper portion (69), there being, extending from the middle portion (65) of the housing (6), a feeding pipe (33) which is arranged to convey water that is entering the housing (6) at the lower portion (60) to the inside of the closed pen (1), and the feeding system comprising a feed hopper (51) and a feeder (53) for carrying a feed out of the feed hopper (51) and up to a mouth (57), the mouth (57) being positioned at the upper portion (69) of the housing (6), and the housing (6) being provided with a passage between the upper portion (69) and the middle portion (65) so that the feed is carried in the water and into the closed pen (1).
