Aspects and embodiments of the present invention are directed to apparatus and methods of filtering a fluid to reduce a level of at least one contaminant therein. The filtering of the fluid may be accomplished with a radial flow filtration column comprising a fluid chamber having an inlet, an outlet, and a side wall, an inner permeable retainer positioned in the fluid chamber, an outer permeable retainer positioned in the fluid chamber spaced apart from and surrounding the inner permeable retainer, a media bed compartment formed between the inner permeable retainer and the outer permeable retainer, and an adjustable element biased into the media bed compartment and configured to maintain a predetermined packing density of a media bed to be disposed within the media bed compartment.