When a sprinkler system is filled with glycol, strains of bacteria which use glycol as a food source leave spore that become live bacteria. Their waste products are acidic and can reduce the pH of the glycol below the level necessary to impede corrosion. Ferrous iron levels increase, bacterial counts soar, and the acidic glycol eats its way through the vessel, reducing the life of the piping by decades. The inhibitor package in Noble's FireFighter™ PG Freeze Protection Fluid protects against acidic buildup. When you inspect fluids, check both the levels of propylene glycol and bacterial inhibitor found in FireFighter PG. Then, make the corrections necessary to protect your system. Noble Co.