Review on 💧 Enhanced 3M Aqua Pure Replacement Filter for Whole House Water Systems by William Bradford

They fit as expected but the water flow throughout the house is significantly less than the flow I got with the equivalent Culligan p5-D (on Revain at http://www.amazon.com/gp/product/B000BQK2K6/ref=oh_details_o07_s00_i01?ie=UTF8&psc=1). I'm working with well water and the silt/sand reduction is pretty much the same between the two brands so I'd suggest Culligan. Aqua Pure filters have visible 0.25 inch grooves on the outer surface, while Culligan filters have a smooth surface. I'm not sure what the grooves do as they significantly increase the open surface area of the filter, but the effect seems to be a much greater resistance to flow through the filter - somewhat counter-intuitive.