Typically, an inhibitor would not be a control location. Our recommendation would be to set this component to “No” as a control location for this reason: Corrosion inhibitors are used to preserve metallic components of building water systems, often in conjunction with other water treatment processes. Corrosion can create environments that can harbor microbial populations, including Legionella. Corrosion inhibitors are not Legionella biocides, and cannot be used to directly control Legionella growth.