When calculating ounces per gallon for stock solution, which values are multiplied in the numerator?

When calculating ounces per gallon for stock solution, which values are multiplied in the numerator?

• A. Injector ratio × Volume
• B. Target ppm ÷ Injector ratio
• C. Fertilizer concentration × Target ppm
• D. Target ppm × Injector ratio

Answer: (D)

This question is about turning a target final concentration (ppm) into the actual amount of stock solution to add per gallon using an injector ratio. To get the correct stock amount, you multiply the desired ppm by the injector ratio. That product represents the amount of stock solution (in ppm-equivalent terms) you need before you account for how concentrated the stock is. The stock’s concentration then sits in the denominator to convert that amount into ounces per gallon. So the numerator should contain the target ppm multiplied by the injector ratio. The fertilizer concentration is used in the denominator to finish the conversion to ounces per gallon. The other pairings mix units in ways that don’t reflect how injector ratios translate ppm into a stock-amount quantity.

This question is about turning a target final concentration (ppm) into the actual amount of stock solution to add per gallon using an injector ratio. To get the correct stock amount, you multiply the desired ppm by the injector ratio. That product represents the amount of stock solution (in ppm-equivalent terms) you need before you account for how concentrated the stock is. The stock’s concentration then sits in the denominator to convert that amount into ounces per gallon.

So the numerator should contain the target ppm multiplied by the injector ratio. The fertilizer concentration is used in the denominator to finish the conversion to ounces per gallon. The other pairings mix units in ways that don’t reflect how injector ratios translate ppm into a stock-amount quantity.