A filtration system and methods for using same are disclosed. The filtration system can include a frame, and a plurality of filters coupled to the frame and coupled to each other in series. A pump can provide a pressure differential that causes fluid to flow through the filters in series. The first filter can be provided as a pre-filter, and one or more additional filters can include pleated, calendared, micro-fiber filters. Another filter can be a percentage removal nano-filter that is adapted to remove sub-micron particles from the fluid. The nano-filter can include three pleated filter layers. Each pleated filter layer can be oriented approximately concentrically about a common longitudinal axis.