wouldnt like to say ian but i thought the idea of a booster pump was to keep pressure up if water is coming through a resin surely this would slow it down . where as a booster pump before would keep pressure same , after all a booster pump is fitted before ro unit . could be wrong in what i say but i would go pump , softner , ro , then di . but thats me what would you do . by the way i cant really see a softner resin gettin in to ro as its in its own pod .