Disclosed is a water inlet arrangement when used in a fish tank in aquaculture. The arrangement comprises a pipe (4) to feed water into the tank. The pipe (4) has a plurality of openings. There is a surrounding element (8) and/ or a fixed or adjustable shield (10). The surrounding element surrounds the pipe (4) and has a plurality of openings. The shield (10) surrounds the plurality of lateral openings of the pipe (4) or surrounds the openings of the surrounding element (8).