Backpack sprayers give gardeners the ability to bring large amounts of liquid to otherwise inaccessible areas of their property. Backpack sprayers resemble hand sprayers in terms of functionality and use, but they tend to hold more liquid. Plus, you carry the device comfortably on your back rather than lugging around a heavy container. The basic usage instructions remain the same regardless of the liquid -- it doesn't matter if you're spraying water, herbicides, pesticides or liquid nutrients.
Assemble the sprayer if it isn't already put together. Instructions vary based on the manufacturer, but typically, you'll have to screw the spray wand onto the spray gun, insert the pump handle into the appropriate hole and attach the shoulder straps.
Prepare the liquid you plan to use in separate container. Herbicides, pesticides and insecticides often need to be mixed with water. Follow all directions on product labelling when mixing chemicals.
Unscrew the cap on the backpack sprayer. Pour the liquid into the sprayer slowly. Avoid dripping chemicals on the ground while you're pouring them.
Screw the cap back on.
Put the backpack sprayer on your back. Tighten the plastic straps until they fit snugly and securely.
Prime the sprayer by pumping the handle between 10 and 15 times. Pump the handle once every five seconds to maintain continuous pressure in the backpack tank; otherwise, you'll need to reprime the sprayer fully whenever the pressure gives out.
Point the wand where you want to spray and pull the trigger to apply the liquid.
Wear all appropriate safety gear when spraying chemicals. Consult product labelling to determine what safety gear is necessary.
Do not use herbicides in a backpack sprayer that was previously used to spray insecticides, or vice versa. If you need to do so, thoroughly clean all parts of the backpack sprayer prior to adding the second chemical.