Abstract: A bar filter is disclosed which is fit for use in an apparatus for removing phosphates from waste water. Thereto phosphates are chemically bound to magnetic material, like magnetite, and subsequently the liquid containing the suspended particles is fed through a filter according to the present invention. The magnetic particles adhere to the bars of the magnetic filter so that the filter gradually fills with the particles. According to the present invention, the configuration of the bars of the filter is such that the gradient of the magnetic field is substantially constant, leading to an even filling of the filter, so that the frequency of flushing the filter to empty it is limited as far as possible. Preferably the density of the bars is a plane perpendicular to the bars is constant.