A system and method for uniformly distributing fluids (e.g., washing and in-service) through a filter bed of a filter. The system and method of the present invention can be used with any type of filter that uses media to remove impurities from a fluid. The filter bed can include one or more layers of media. The media can be natural (e.g., sand, gravel, anthracite, etc.) or can be fabricated (e.g., plastic). The filter media can be supported by one or more layers of gravel. Alternatively, the filter media can be supported by a porous plate or other support designed to replace the gravel layers. The present invention includes a system having one or more distribution members configured to uniformly distribute a fluid through a filter bed of a filter. Preferably, the one or more distribution members can be readily installed by relatively unskilled labor in both existing filters and new filters. In a preferred embodiment, the one or more distribution members are configured to extend into at least a portion of an underdrain from above the underdrain. In retrofit applications, the preferred design of the one or more distribution members is such that no significant alteration of the distribution chamber, underdrain or fluid velocity is necessary.