An injection element for injecting a fluid into a tank

An injection element for injecting a fluid into a tank, especially for injecting water into the tank, especially into a fish tank,

• wherein the injection element comprises an outer pipe and an inner pipe arranged at least partially inside the outer pipe,
• wherein the inner pipe is extractable at least partially out of an outlet end of the outer pipe,
• wherein an inlet end of the outer pipe is configured to be connected with a fluid providing device, and
• wherein the outer pipe is configured to be arranged mainly outside of an interior volume of the tank and an outlet end of the outer pipe is configured to be connected with an opening in a wall of the tank wherein the injection element is so configured that it always have a fluid communication to the tank regardless of the extraction of the inner pipe.