The present application relates to a filtration system (1) having at least one flexible filter (9) and cleaning apparatus (25) for projecting a flow of fluid onto the at least one flexible filter. The fluid to be filtered passes through the at least cone flexible filter (9) and causes the at least one flexible filter (9) to be deflected in a first direction. The flow of fluid projected onto the at least one flexible filter (9) from the cleaning apparatus (25) causes the at least one flexible filter (9) to be deflected in a second direction. The first and second directions are substantially opposite to each other. The present invention further relates to a filtration system (1) for filtering particulates from a liquid. The filtration system has a sealed vessel (2) suitable for supporting a pressure less than atmospheric pressure. A filter (9) is provided for filtering particulates from the liquid. The application also relates to a method of filtering fluid.