Scaling, fouling and oxidation are the natural enemies of reverse osmosis (RO) systems in water processing units—especially in the food and pharmaceutical industries. Proper process monitoring and control of critical parameters, such as pH, ORP, conductivity, flow, temperature and differential pressure can provide advanced warning and protection of a scaling, fouling or chemically attacked RO element. If these early warnings are ignored, the membrane may be damaged beyond the point that chemical cleaning can restore the system back to its original operating efficiency.