High pH liquid RO membrane cleaning formulation for disintegration of gypsum scale.


  • High strength liquid formulation specifically designed for removal of gypsum scale
  • Chelates and disintegrates gypsum (calcium sulfate dihydrate scale) into a slurry that can easily be flushed from the membrane surface and that has a much larger exposed surface area for chelation where necessary
  • Effectively penetrates and removes organic and biological foulants
  • Can be followed with AWC C-239 cleaning for complete removal of the most stubborn sulfate scales
  • Compatible with all Thin Film Composite RO membranes from all major membrane suppliers
  • Halal & Kosher certified
  • Certified by NSF to NSF/ANSI/CAN Standard 60: Drinking Water Treatment

Typical Properties

  • Appearance:  Clear yellow liquid
  • Odor: Slight characteristic
  • Solubility: Complete


  • 5 gallon pails
  • 55 gallon non-returnable plastic drums
  • 275 gallon totes

Safety and Handling

Store in cool, dry and well ventilated area. Keep containers closed. Wash contaminated clothes before re-use. Wash thoroughly after handling. For more information, see the Safety Data Sheet provided with this product.

Chemical Feeding and Control

The cleaning solution should be prepared using RO permeate or softened water that is free of residual chlorine or other oxidizing agents. The solution is prepared by adding 17 lbs of AWC C-238 for every 100 gallons of water (2 % by wt. Solution). The cleaning solution is then circulated throughout the system without exceeding pressures, temperatures and flow rates recommended by the membrane manufacturer. Cleaning efficacy can be further improved by heating the cleaning solution and alternately circulating the solution for 60 minutes and then soaking the membranes for 30- 60 minutes for a total cleaning time of 4-6 hours. AWC C-238 should be added as necessary to the cleaning solution to maintain the pH range throughout the entire cleaning process. Following this cleaning with C-239 low pH cleaning compound is recommended for stubborn calcium sulfate scale. Depending on severity of fouling, your AWC representative will recommend optimal cleaning times.