SRC MCC-1, or Membrane Cleaning Compound “#1”, is an alkaline cleaner designed to clean biological and slight oil fouling. Biological growth is fairly common and occurs because the System is constantly exposed to seawater. If exposed to seawater while not in operation, the RO Membrane Element can still become fouled. To keep biological fouling at a minimum, rinse the System with fresh water when not in use. Cleaning procedure is mentioned in the System’s Manual and on the MCC-1 package