A water filtration and disinfection device comprises a water basin having an inlet for receiving water from a source. A sidestream treatment device is provided for treating water from the water basin, and the sidestream treatment device comprises a plurality of filtration or disinfection mechanisms for acting on water within the sidestream treatment device. A feed conduit extends between the water basin and the sidestream treatment device for feeding water from the water basin to the sidestream and a return conduit extends from the sidestream treatment device to the water basin for returning at least a part of the water to the water basin.