What is the procedure for cleaning RO membrane? What chemicals should be used? How can we determine whether the membranes in our Reverse Osmosis system are damaged? Please suggest an appropriate antiscalant and dosage for use with feed water having a TDS of 1500 ppm 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?