Sprayer Calibration Guide for Small Hand Pump Sprayers Used In Aquaponics

Article written by: Jason Danaher Ph.D. 

A handheld, one-gallon, pump sprayer (Figure 1) is an inexpensive, yet effective technology a small farmer can use to apply fertilizers, pesticides, herbicides, and non-harsh cleaners in and around your fish and/or plant production area. However, proper treatment starts with the calibration of your spraying equipment before chemical application. This ensures the correct concentration/quantity of fertilizer, pesticide, herbicide or cleaner is applied according to the product label. To calibrate hand pump sprayers, follow these basic steps:

Important Tips to Remember

• Check the sprayer operator's manual for recommended procedures regarding safe use of equipment.

• DO NOT use pesticide during calibration. Calibrations should be done with only water in the tank and in calm air, with wind not exceeding 7 miles per hour.

• A spray colorant is optional to aid in determining spray pattern, droplet size, coverage and pressure. Be aware the dye may result in a temporary or permanent color change of the material it contacts.

• Select the proper equipment for the job and maintain the equipment for optimal operation. This includes inspecting nozzles, pumps, hoses, pressure regulators, etc. to ensure they are in ideal condition.

• Wear the correct Personal Protective Equipment (PPE) (i.e. nitrile gloves, eye protection, clothing) you will use when applying the tank mix.

• Adjustments in the rate of travel, nozzle height, or tank pressure can affect the amount of mixture dispersed; therefore, maintain speed and tank pressure throughout the application process. 

• Re-check hand pump sprayer calibration periodically.

Figure 1. A one-gallon handheld sprayer used to disperse tank mixes at low pressures for controlled application of fertilizers, pesticides, herbicides, and non-harsh cleaners.

Steps:

1. Measure a 10’ x 25’ or 250 ft² area.

2. Dress in the appropriate PPE you will be wearing during the actual application. Refer to the product label.

3. Fill the one-gallon sprayer with water (and optional dye) to the one-gallon graduation mark on the sprayer.

4. Maintain your walking speed and constant pressure in the vessel as you spray the 250 ft² area. Initially you may need to adjust the spray nozzle to get the desired spray pattern (i.e. fine mist to strong stream).

5. After covering the 250 ft² area you will need to quantify the amount of water remaining in the 1-gallon sprayer with a graduated cylinder or measuring cup. 

i. Step #2 - Step #4 = Spray volume per 250 ft²

Example: 1.0 gallon - 0.77 gallons = 0.23 gallons per 250 ft²

6. Now based on #5 results you can calculate the volume of tank mix required to treat your growing area. Let’s say your growing area has a total dimension of 24’ × 80’. This equates to a total area of 1,920 ft².

Use the following formula to determine the volume of tank mix required.

You now know based on your calibration exercise that 1.77 gallons of tank mix is required to treat 1,920 ft². This will require filling the one-gallon sprayer two (2) times to complete the full treatment. Now that you know the volume of tank mix the calibrated sprayer will discharge, you can now refer to the fertilizer, pesticide, or herbicide product label and calculate its volume to add into the one-gallon sprayer.

You will end up with approximately 0.25 gallons of tank mix remaining after treating the 1,920 ft²area. You can either apply it to another area at your production facility to treat for the same pests or refer to the product label and store it appropriately for a future treatment or properly dispose of the tank mix.

Feel free to contact Aquatic Equipment and Design, Inc. at 407-995-6490 or email info@aquaticed.com to clarify the calibration process.