An air scrubber system including a system for creating an oxidation reduction potential (ORP) in water is disclosed. The system includes a pipe assembly for in-line mixing. The pipe assembly includes a first flow path for water to flow through. The first flow path includes one or more ozone intake ports that are fluidically coupled to one or more ozone output ports of an ozone supply unit. The pipe assembly further includes a second flow path fluidically coupled in parallel with the first flow path. The second flow path includes a control valve that selectively permits a portion of the water to flow through the second flow path to produce a negative pressure in the first flow path so that ozone is drawn into the first flow path through the one or more ozone intake ports and mixed into the water flowing through the first flow path.