How do you calculate lb of chemical per CFS?

To calculate pounds of chemical per cubic feet per second (CFS), it is essential to understand how parts per million weight (PPMW) relates to the volume of water flowing through a system. The correct formula incorporates two critical factors: the flow rate in CFS and the conversion factor that translates the concentration of the chemical from parts per million to pounds.

The chosen answer correctly utilizes the relationship between PPMW, flow rate, and time. Specifically, starting with PPMW, which represents the concentration of the chemical, the formula multiplies by 3744 to convert PPM to the number of pounds in one million gallons of water. The multiplication also considers the time factor, expressed in minutes, to accurately reflect the amount of chemical applied over that period. Dividing by one million standardizes the units since PPMW is typically founded on a million parts, ensuring that the values align correctly.

In summary, the formula effectively combines the concentration of the chemical, the flow rate of water, and the time of application into a coherent measurement of pounds of chemical per CFS, which is vital for proper calculations in aquatic pest control practices.