The invention relates to a chamber for a blood treatment system comprising at least one compartment delimited by a chamber wall as well as at least one blood inlet and at least one inlet for a further fluid which are in communication with the compartment wherein both the at least one blood inlet and the at least one inlet for the further fluid are formed on tube pieces which protrude into the compartment of the chamber wherein in the operational state of the chamber the compartment of the chamber is filled at least partially with blood or with a mixture of blood and the further fluid or another fluid and wherein at least one preferably both or a plurality of the tube pieces have a length such that the blood inlet and/or the inlet for the further fluid are located below the blood or fluid level in the chamber.
