If silica is not removed by ion exchange, does that mean it is colloidal silica? We recently installed new RO membranes in our system and observed that the permeate water tested positive for coliform bacteria. Is it possible in your experience that RO membranes could be damaged during installation and cause contamination of the water distribution system by bacteria and pathogens? What does differential pressure or delta P (ΔP) mean when logging RO data? Why does the RO permeate pH rise when the water passes through a degasifier? Does that higher pH really stabilize the RO permeate to help prevent corrosion in the distribution system?